21737270256 has 160 divisors (see below), whose sum is σ = 61691051520. Its totient is φ = 6554956800.

The previous prime is 21737270251. The next prime is 21737270293. The reversal of 21737270256 is 65207273712.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21737270251) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7929046 + ... + 7931786.

It is an arithmetic number, because the mean of its divisors is an integer number (385569072).

Almost surely, 2^21737270256 is an apocalyptic number.

21737270256 is a gapful number since it is divisible by the number (26) 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 21737270256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30845525760).

21737270256 is an abundant number, since it is smaller than the sum of its proper divisors (39953781264).

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

21737270256 is a wasteful number, since it uses less digits than its factorization.

21737270256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3015 (or 3009 counting only the distinct ones).

The product of its (nonzero) digits is 246960, while the sum is 42.

The spelling of 21737270256 in words is "twenty-one billion, seven hundred thirty-seven million, two hundred seventy thousand, two hundred fifty-six".