21616238072 has 64 divisors (see below), whose sum is σ = 50417186400. Its totient is φ = 8536227840.

The previous prime is 21616238071. The next prime is 21616238219. The reversal of 21616238072 is 27083261612.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21616238071) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 536297 + ... + 575192.

Almost surely, 2^21616238072 is an apocalyptic number.

21616238072 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21616238072 is an abundant number, since it is smaller than the sum of its proper divisors (28800948328).

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

21616238072 is a wasteful number, since it uses less digits than its factorization.

21616238072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1111536 (or 1111532 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 38.

Adding to 21616238072 its reverse (27083261612), we get a palindrome (48699499684).

The spelling of 21616238072 in words is "twenty-one billion, six hundred sixteen million, two hundred thirty-eight thousand, seventy-two".