21532267656 has 24 divisors (see below), whose sum is σ = 58316558430. Its totient is φ = 7177422528.

The previous prime is 21532267639. The next prime is 21532267657. The reversal of 21532267656 is 65676223512.

21532267656 is a `hidden beast` number, since 2 + 1 + 532 + 2 + 67 + 6 + 56 = 666.

It can be written as a sum of positive squares in only one way, i.e., 19619604900 + 1912662756 = 140070^2 + 43734^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is not an unprimeable number, because it can be changed into a prime (21532267657) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 149529565 + ... + 149529708.

Almost surely, 2^21532267656 is an apocalyptic number.

It is an amenable number.

21532267656 is an abundant number, since it is smaller than the sum of its proper divisors (36784290774).

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

21532267656 is a wasteful number, since it uses less digits than its factorization.

21532267656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 299059285 (or 299059278 counting only the distinct ones).

The product of its digits is 907200, while the sum is 45.

The spelling of 21532267656 in words is "twenty-one billion, five hundred thirty-two million, two hundred sixty-seven thousand, six hundred fifty-six".