31220739 has 12 divisors (see below), whose sum is σ = 49196472. Its totient is φ = 18921600.

The previous prime is 31220731. The next prime is 31220747. The reversal of 31220739 is 93702213.

It is an interprime number because it is at equal distance from previous prime (31220731) and next prime (31220747).

It is not a de Polignac number, because 31220739 - 2³ = 31220731 is a prime.

It is a super-2 number, since 2×31220739² = 1949469087412242, which contains 22 as substring.

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (31220731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 157582 + ... + 157779.

It is an arithmetic number, because the mean of its divisors is an integer number (4099706).

Almost surely, 2^31220739 is an apocalyptic number.

31220739 is a deficient number, since it is larger than the sum of its proper divisors (17975733).

31220739 is a wasteful number, since it uses less digits than its factorization.

31220739 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 315378 (or 315375 counting only the distinct ones).

The product of its (nonzero) digits is 2268, while the sum is 27.

The square root of 31220739 is about 5587.5521474077. The cubic root of 31220739 is about 314.8819209737.

The spelling of 31220739 in words is "thirty-one million, two hundred twenty thousand, seven hundred thirty-nine".