31000440 has 32 divisors (see below), whose sum is σ = 93001680. Its totient is φ = 8266752.

The previous prime is 31000439. The next prime is 31000471. The reversal of 31000440 is 4400013.

It is a super-2 number, since 2×31000440² = 1922054560387200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

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 in 7 ways as a sum of consecutive naturals, for example, 129049 + ... + 129288.

Almost surely, 2^31000440 is an apocalyptic number.

31000440 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

31000440 is an abundant number, since it is smaller than the sum of its proper divisors (62001240).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31000440 is a wasteful number, since it uses less digits than its factorization.

31000440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 258351 (or 258347 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 12.

The square root of 31000440 is about 5567.8038758563. The cubic root of 31000440 is about 314.1395514767.

Adding to 31000440 its reverse (4400013), we get a palindrome (35400453).

The spelling of 31000440 in words is "thirty-one million, four hundred forty", and thus it is an aban number.