19845540 has 192 divisors, whose sum is σ = 72817920. Its totient is φ = 4423680.

The previous prime is 19845533. The next prime is 19845547. The reversal of 19845540 is 4554891.

It is an interprime number because it is at equal distance from previous prime (19845533) and next prime (19845547).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 19845495 and 19845504.

It is not an unprimeable number, because it can be changed into a prime (19845547) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 77092 + ... + 77348.

It is an arithmetic number, because the mean of its divisors is an integer number (379260).

Almost surely, 2^19845540 is an apocalyptic number.

19845540 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 19845540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36408960).

19845540 is an abundant number, since it is smaller than the sum of its proper divisors (52972380).

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

19845540 is a wasteful number, since it uses less digits than its factorization.

19845540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 299 (or 291 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 36.

The square root of 19845540 is about 4454.8333302156. The cubic root of 19845540 is about 270.7411734295.

The spelling of 19845540 in words is "nineteen million, eight hundred forty-five thousand, five hundred forty".