21538960331 has 12 divisors (see below), whose sum is σ = 25732703808. Its totient is φ = 17962992432.

The previous prime is 21538960319. The next prime is 21538960379. The reversal of 21538960331 is 13306983512.

It is a happy number.

It is not a de Polignac number, because 21538960331 - 2¹⁰ = 21538959307 is a prime.

It is a super-2 number, since 2×21538960331² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21538960381) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5938331 + ... + 5941956.

It is an arithmetic number, because the mean of its divisors is an integer number (2144391984).

Almost surely, 2^21538960331 is an apocalyptic number.

21538960331 is a deficient number, since it is larger than the sum of its proper divisors (4193743477).

21538960331 is a wasteful number, since it uses less digits than its factorization.

21538960331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11880338 (or 11880331 counting only the distinct ones).

The product of its (nonzero) digits is 116640, while the sum is 41.

The spelling of 21538960331 in words is "twenty-one billion, five hundred thirty-eight million, nine hundred sixty thousand, three hundred thirty-one".