16165765440 has 672 divisors, whose sum is σ = 64704407040. Its totient is φ = 3663360000.

The previous prime is 16165765439. The next prime is 16165765457. The reversal of 16165765440 is 4456756161.

16165765440 is a `hidden beast` number, since 16 + 16 + 576 + 54 + 4 + 0 = 666.

It is a super-2 number, since 2×16165765440² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 64405315 + ... + 64405565.

It is an arithmetic number, because the mean of its divisors is an integer number (96286320).

Almost surely, 2^16165765440 is an apocalyptic number.

16165765440 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 16165765440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32352203520).

16165765440 is an abundant number, since it is smaller than the sum of its proper divisors (48538641600).

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

16165765440 is a wasteful number, since it uses less digits than its factorization.

16165765440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 411 (or 398 counting only the distinct ones).

The product of its (nonzero) digits is 604800, while the sum is 45.

The spelling of 16165765440 in words is "sixteen billion, one hundred sixty-five million, seven hundred sixty-five thousand, four hundred forty".