31742640 has 60 divisors (see below), whose sum is σ = 106604784. Its totient is φ = 8464512.

The previous prime is 31742611. The next prime is 31742647. The reversal of 31742640 is 4624713.

31742640 is a `hidden beast` number, since 3 + 17 + 4 + 2 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (60).

It is not an unprimeable number, because it can be changed into a prime (31742647) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 21324 + ... + 22763.

Almost surely, 2^31742640 is an apocalyptic number.

31742640 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

31742640 is an abundant number, since it is smaller than the sum of its proper divisors (74862144).

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

31742640 is a wasteful number, since it uses less digits than its factorization.

31742640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44106 (or 44097 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 27.

The square root of 31742640 is about 5634.0607025484. The cubic root of 31742640 is about 316.6268069251.

The spelling of 31742640 in words is "thirty-one million, seven hundred forty-two thousand, six hundred forty".