31475640 has 192 divisors, whose sum is σ = 113024160. Its totient is φ = 6988800.

The previous prime is 31475623. The next prime is 31475669. The reversal of 31475640 is 4657413.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 31475598 and 31475607.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 311590 + ... + 311690.

Almost surely, 2^31475640 is an apocalyptic number.

31475640 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31475640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (56512080).

31475640 is an abundant number, since it is smaller than the sum of its proper divisors (81548520).

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

31475640 is a wasteful number, since it uses less digits than its factorization.

31475640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 182 (or 171 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 30.

The square root of 31475640 is about 5610.3154991498. The cubic root of 31475640 is about 315.7365480309.

The spelling of 31475640 in words is "thirty-one million, four hundred seventy-five thousand, six hundred forty".