21506236532 has 36 divisors (see below), whose sum is σ = 42486501540. Its totient is φ = 9511349760.

The previous prime is 21506236519. The next prime is 21506236537. The reversal of 21506236532 is 23563260512.

It can be written as a sum of positive squares in 2 ways, for example, as 8509324516 + 12996912016 = 92246^2 + 114004^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21506236492 and 21506236501.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21506236537) 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, 582557 + ... + 618372.

Almost surely, 2^21506236532 is an apocalyptic number.

21506236532 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21506236532 is a deficient number, since it is larger than the sum of its proper divisors (20980265008).

21506236532 is a wasteful number, since it uses less digits than its factorization.

21506236532 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1200992 (or 1200979 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 35.

The spelling of 21506236532 in words is "twenty-one billion, five hundred six million, two hundred thirty-six thousand, five hundred thirty-two".