21550500531 has 24 divisors (see below), whose sum is σ = 35580246624. Its totient is φ = 12312904320.

The previous prime is 21550500523. The next prime is 21550500553. The reversal of 21550500531 is 13500505512.

21550500531 is a `hidden beast` number, since 2 + 155 + 0 + 500 + 5 + 3 + 1 = 666.

It is not a de Polignac number, because 21550500531 - 2³ = 21550500523 is a prime.

It is a super-2 number, since 2×21550500531² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21550500495 and 21550500504.

It is not an unprimeable number, because it can be changed into a prime (21550500571) 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 23 ways as a sum of consecutive naturals, for example, 562375 + ... + 599471.

It is an arithmetic number, because the mean of its divisors is an integer number (1482510276).

Almost surely, 2^21550500531 is an apocalyptic number.

21550500531 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21550500531 is a deficient number, since it is larger than the sum of its proper divisors (14029746093).

21550500531 is a wasteful number, since it uses less digits than its factorization.

21550500531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46331 (or 46328 counting only the distinct ones).

The product of its (nonzero) digits is 3750, while the sum is 27.

The spelling of 21550500531 in words is "twenty-one billion, five hundred fifty million, five hundred thousand, five hundred thirty-one".