161051220 has 192 divisors, whose sum is σ = 575769600. Its totient is φ = 36961920.

The previous prime is 161051207. The next prime is 161051249. The reversal of 161051220 is 22150161.

161051220 is a `hidden beast` number, since 1 + 610 + 51 + 2 + 2 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 161051193 and 161051202.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 112147 + ... + 113573.

It is an arithmetic number, because the mean of its divisors is an integer number (2998800).

Almost surely, 2^161051220 is an apocalyptic number.

161051220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 161051220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (287884800).

161051220 is an abundant number, since it is smaller than the sum of its proper divisors (414718380).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161051220 is a wasteful number, since it uses less digits than its factorization.

161051220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1475 (or 1467 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 18.

The square root of 161051220 is about 12690.5957306976. The cubic root of 161051220 is about 544.0698664952.

The spelling of 161051220 in words is "one hundred sixty-one million, fifty-one thousand, two hundred twenty".