31540039393 has 4 divisors (see below), whose sum is σ = 31541367060. Its totient is φ = 31538711728.

The previous prime is 31540039381. The next prime is 31540039423. The reversal of 31540039393 is 39393004513.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 39393004513 = 19 ⋅2073316027.

It can be written as a sum of positive squares in 2 ways, for example, as 19194162849 + 12345876544 = 138543^2 + 111112^2 .

It is a cyclic number.

It is not a de Polignac number, because 31540039393 - 2¹⁷ = 31539908321 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31540039693) 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, 627538 + ... + 675931.

It is an arithmetic number, because the mean of its divisors is an integer number (7885341765).

Almost surely, 2^31540039393 is an apocalyptic number.

It is an amenable number.

31540039393 is a deficient number, since it is larger than the sum of its proper divisors (1327667).

31540039393 is a wasteful number, since it uses less digits than its factorization.

31540039393 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1327666.

The product of its (nonzero) digits is 131220, while the sum is 40.

The spelling of 31540039393 in words is "thirty-one billion, five hundred forty million, thirty-nine thousand, three hundred ninety-three".