31720090 has 16 divisors (see below), whose sum is σ = 57621960. Its totient is φ = 12571200.

The previous prime is 31720049. The next prime is 31720103. The reversal of 31720090 is 9002713.

It can be written as a sum of positive squares in 4 ways, for example, as 18258529 + 13461561 = 4273^2 + 3669^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13461 + ... + 15640.

Almost surely, 2^31720090 is an apocalyptic number.

31720090 is a deficient number, since it is larger than the sum of its proper divisors (25901870).

31720090 is a wasteful number, since it uses less digits than its factorization.

31720090 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29217.

The product of its (nonzero) digits is 378, while the sum is 22.

The square root of 31720090 is about 5632.0591261101. The cubic root of 31720090 is about 316.5518118406.

The spelling of 31720090 in words is "thirty-one million, seven hundred twenty thousand, ninety".