31248792821 has 2 divisors, whose sum is σ = 31248792822. Its totient is φ = 31248792820.

The previous prime is 31248792803. The next prime is 31248792931. The reversal of 31248792821 is 12829784213.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25848600625 + 5400192196 = 160775^2 + 73486^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31248792821 is a prime.

It is a super-2 number, since 2×31248792821² (a number of 22 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31248792221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15624396410 + 15624396411.

It is an arithmetic number, because the mean of its divisors is an integer number (15624396411).

Almost surely, 2^31248792821 is an apocalyptic number.

It is an amenable number.

31248792821 is a deficient number, since it is larger than the sum of its proper divisors (1).

31248792821 is an equidigital number, since it uses as much as digits as its factorization.

31248792821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 387072, while the sum is 47.

The spelling of 31248792821 in words is "thirty-one billion, two hundred forty-eight million, seven hundred ninety-two thousand, eight hundred twenty-one".