19901456256 has 128 divisors (see below), whose sum is σ = 57739703040. Its totient is φ = 6023352320.

The previous prime is 19901456243. The next prime is 19901456279. The reversal of 19901456256 is 65265410991.

It is a tau number, because it is divible by the number of its divisors (128).

It is a super-2 number, since 2×19901456256² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (48).

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 15 ways as a sum of consecutive naturals, for example, 4149796 + ... + 4154588.

It is an arithmetic number, because the mean of its divisors is an integer number (451091430).

Almost surely, 2^19901456256 is an apocalyptic number.

19901456256 is a gapful number since it is divisible by the number (16) 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 19901456256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28869851520).

19901456256 is an abundant number, since it is smaller than the sum of its proper divisors (37838246784).

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

19901456256 is a wasteful number, since it uses less digits than its factorization.

19901456256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5804 (or 5792 counting only the distinct ones).

The product of its (nonzero) digits is 583200, while the sum is 48.

The spelling of 19901456256 in words is "nineteen billion, nine hundred one million, four hundred fifty-six thousand, two hundred fifty-six".