31532708821 has 4 divisors (see below), whose sum is σ = 31561454412. Its totient is φ = 31503963232.

The previous prime is 31532708773. The next prime is 31532708839. The reversal of 31532708821 is 12880723513.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 6070123921 + 25462584900 = 77911^2 + 159570^2 .

It is a cyclic number.

It is not a de Polignac number, because 31532708821 - 2²⁷ = 31398491093 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31532708321) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14371150 + ... + 14373343.

It is an arithmetic number, because the mean of its divisors is an integer number (7890363603).

Almost surely, 2^31532708821 is an apocalyptic number.

It is an amenable number.

31532708821 is a deficient number, since it is larger than the sum of its proper divisors (28745591).

31532708821 is a wasteful number, since it uses less digits than its factorization.

31532708821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28745590.

The product of its (nonzero) digits is 80640, while the sum is 40.

The spelling of 31532708821 in words is "thirty-one billion, five hundred thirty-two million, seven hundred eight thousand, eight hundred twenty-one".