21620136272 has 20 divisors (see below), whose sum is σ = 47873159136. Its totient is φ = 9265772640.

The previous prime is 21620136217. The next prime is 21620136287. The reversal of 21620136272 is 27263102612.

It is a super-3 number, since 3×21620136272³ (a number of 32 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 96518354 + ... + 96518577.

Almost surely, 2^21620136272 is an apocalyptic number.

It is an amenable number.

21620136272 is an abundant number, since it is smaller than the sum of its proper divisors (26253022864).

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

21620136272 is a wasteful number, since it uses less digits than its factorization.

21620136272 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 193036946 (or 193036940 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 32.

Adding to 21620136272 its reverse (27263102612), we get a palindrome (48883238884).

The spelling of 21620136272 in words is "twenty-one billion, six hundred twenty million, one hundred thirty-six thousand, two hundred seventy-two".