165091521400 has 48 divisors (see below), whose sum is σ = 413363777400. Its totient is φ = 60956868480.

The previous prime is 165091521383. The next prime is 165091521403. The reversal of 165091521400 is 4125190561.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165091521403) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 31745770 + ... + 31750969.

Almost surely, 2^165091521400 is an apocalyptic number.

165091521400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

165091521400 is an abundant number, since it is smaller than the sum of its proper divisors (248272256000).

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

165091521400 is a wasteful number, since it uses less digits than its factorization.

165091521400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63496768 (or 63496759 counting only the distinct ones).

The product of its (nonzero) digits is 10800, while the sum is 34.

The spelling of 165091521400 in words is "one hundred sixty-five billion, ninety-one million, five hundred twenty-one thousand, four hundred".