31481780 has 36 divisors (see below), whose sum is σ = 72673860. Its totient is φ = 11447040.

The previous prime is 31481767. The next prime is 31481819. The reversal of 31481780 is 8718413.

It can be written as a sum of positive squares in 2 ways, for example, as 8690704 + 22791076 = 2948^2 + 4774^2 .

It is a super-2 number, since 2×31481780² = 1982204943936800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4085 + ... + 8924.

Almost surely, 2^31481780 is an apocalyptic number.

It is an amenable number.

31481780 is an abundant number, since it is smaller than the sum of its proper divisors (41192080).

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

31481780 is a wasteful number, since it uses less digits than its factorization.

31481780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13040 (or 13027 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 32.

The square root of 31481780 is about 5610.8626787687. The cubic root of 31481780 is about 315.7570770957.

The spelling of 31481780 in words is "thirty-one million, four hundred eighty-one thousand, seven hundred eighty".