21131552535 has 16 divisors (see below), whose sum is σ = 34901145600. Its totient is φ = 10906607520.

The previous prime is 21131552503. The next prime is 21131552539. The reversal of 21131552535 is 53525513112.

It is a happy number.

It is not a de Polignac number, because 21131552535 - 2⁵ = 21131552503 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21131552496 and 21131552505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21131552539) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22721635 + ... + 22722564.

It is an arithmetic number, because the mean of its divisors is an integer number (2181321600).

Almost surely, 2^21131552535 is an apocalyptic number.

21131552535 is a deficient number, since it is larger than the sum of its proper divisors (13769593065).

21131552535 is a wasteful number, since it uses less digits than its factorization.

21131552535 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45444238.

The product of its digits is 22500, while the sum is 33.

The spelling of 21131552535 in words is "twenty-one billion, one hundred thirty-one million, five hundred fifty-two thousand, five hundred thirty-five".