31225540 has 24 divisors (see below), whose sum is σ = 66407040. Its totient is φ = 12331488.

The previous prime is 31225507. The next prime is 31225541. The reversal of 31225540 is 4552213.

It is not an unprimeable number, because it can be changed into a prime (31225541) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8302 + ... + 11461.

It is an arithmetic number, because the mean of its divisors is an integer number (2766960).

Almost surely, 2^31225540 is an apocalyptic number.

It is an amenable number.

31225540 is an abundant number, since it is smaller than the sum of its proper divisors (35181500).

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

31225540 is a wasteful number, since it uses less digits than its factorization.

31225540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19851 (or 19849 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 22.

The square root of 31225540 is about 5587.9817465700. The cubic root of 31225540 is about 314.8980605726.

Adding to 31225540 its reverse (4552213), we get a palindrome (35777753).

It can be divided in two parts, 312 and 25540, that added together give a palindrome (25852).

The spelling of 31225540 in words is "thirty-one million, two hundred twenty-five thousand, five hundred forty".