231621564 has 24 divisors (see below), whose sum is σ = 553020160. Its totient is φ = 75411504.

The previous prime is 231621563. The next prime is 231621581. The reversal of 231621564 is 465126132.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231621563) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 223924 + ... + 224955.

Almost surely, 2^231621564 is an apocalyptic number.

It is an amenable number.

231621564 is an abundant number, since it is smaller than the sum of its proper divisors (321398596).

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

231621564 is a wasteful number, since it uses less digits than its factorization.

231621564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 448929 (or 448927 counting only the distinct ones).

The product of its digits is 8640, while the sum is 30.

The square root of 231621564 is about 15219.1183713118. The cubic root of 231621564 is about 614.1290812162.

Adding to 231621564 its reverse (465126132), we get a palindrome (696747696).

The spelling of 231621564 in words is "two hundred thirty-one million, six hundred twenty-one thousand, five hundred sixty-four".