16400555520 has 160 divisors (see below), whose sum is σ = 55515116448. Its totient is φ = 4116185088.

The previous prime is 16400555497. The next prime is 16400555581. The reversal of 16400555520 is 2555500461.

It is a tau number, because it is divible by the number of its divisors (160).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 67752 + ... + 193368.

Almost surely, 2^16400555520 is an apocalyptic number.

16400555520 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 16400555520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27757558224).

16400555520 is an abundant number, since it is smaller than the sum of its proper divisors (39114560928).

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

16400555520 is a wasteful number, since it uses less digits than its factorization.

16400555520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125660 (or 125644 counting only the distinct ones).

The product of its (nonzero) digits is 30000, while the sum is 33.

The spelling of 16400555520 in words is "sixteen billion, four hundred million, five hundred fifty-five thousand, five hundred twenty".