21231532631 has 4 divisors (see below), whose sum is σ = 21292718952. Its totient is φ = 21170346312.

The previous prime is 21231532603. The next prime is 21231532633. The reversal of 21231532631 is 13623513212.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21231532631 - 2¹⁴ = 21231516247 is a prime.

It is a super-2 number, since 2×21231532631² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21231532594 and 21231532603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21231532633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30592640 + ... + 30593333.

It is an arithmetic number, because the mean of its divisors is an integer number (5323179738).

Almost surely, 2^21231532631 is an apocalyptic number.

21231532631 is a deficient number, since it is larger than the sum of its proper divisors (61186321).

21231532631 is an equidigital number, since it uses as much as digits as its factorization.

21231532631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61186320.

The product of its digits is 6480, while the sum is 29.

The spelling of 21231532631 in words is "twenty-one billion, two hundred thirty-one million, five hundred thirty-two thousand, six hundred thirty-one".