31440164 has 18 divisors (see below), whose sum is σ = 64003590. Its totient is φ = 13474272.

The previous prime is 31440161. The next prime is 31440173. The reversal of 31440164 is 46104413.

It can be written as a sum of positive squares in only one way, i.e., 23600164 + 7840000 = 4858^2 + 2800^2 .

It is not an unprimeable number, because it can be changed into a prime (31440161) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 80009 + ... + 80400.

It is an arithmetic number, because the mean of its divisors is an integer number (3555755).

Almost surely, 2^31440164 is an apocalyptic number.

It is an amenable number.

31440164 is an abundant number, since it is smaller than the sum of its proper divisors (32563426).

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

31440164 is a wasteful number, since it uses less digits than its factorization.

31440164 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160427 (or 160418 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 31440164 is about 5607.1529317471. The cubic root of 31440164 is about 315.6178818641.

Adding to 31440164 its reverse (46104413), we get a palindrome (77544577).

The spelling of 31440164 in words is "thirty-one million, four hundred forty thousand, one hundred sixty-four".