31172240 has 40 divisors (see below), whose sum is σ = 79066368. Its totient is φ = 11335040.

The previous prime is 31172209. The next prime is 31172243. The reversal of 31172240 is 4227113.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (31172243) by changing a digit.

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, 16832 + ... + 18591.

Almost surely, 2^31172240 is an apocalyptic number.

It is an amenable number.

31172240 is an abundant number, since it is smaller than the sum of its proper divisors (47894128).

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

31172240 is a wasteful number, since it uses less digits than its factorization.

31172240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35447 (or 35441 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 20.

The square root of 31172240 is about 5583.2105459135. The cubic root of 31172240 is about 314.7187882476.

Adding to 31172240 its reverse (4227113), we get a palindrome (35399353).

It can be divided in two parts, 31 and 172240, that added together give a palindrome (172271).

The spelling of 31172240 in words is "thirty-one million, one hundred seventy-two thousand, two hundred forty".