31021213738 has 4 divisors (see below), whose sum is σ = 46531820610. Its totient is φ = 15510606868.

The previous prime is 31021213711. The next prime is 31021213781. The reversal of 31021213738 is 83731212013.

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

It can be written as a sum of positive squares in only one way, i.e., 27791223849 + 3229989889 = 166707^2 + 56833^2 .

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 7755303433 + ... + 7755303436.

Almost surely, 2^31021213738 is an apocalyptic number.

31021213738 is a deficient number, since it is larger than the sum of its proper divisors (15510606872).

31021213738 is a wasteful number, since it uses less digits than its factorization.

31021213738 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15510606871.

The product of its (nonzero) digits is 6048, while the sum is 31.

The spelling of 31021213738 in words is "thirty-one billion, twenty-one million, two hundred thirteen thousand, seven hundred thirty-eight".