31397130 has 48 divisors (see below), whose sum is σ = 86438664. Its totient is φ = 7879680.

The previous prime is 31397129. The next prime is 31397143. The reversal of 31397130 is 3179313.

It can be written as a sum of positive squares in 4 ways, for example, as 29582721 + 1814409 = 5439^2 + 1347^2 .

It is a junction number, because it is equal to n+sod(n) for n = 31397094 and 31397103.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 8731 + ... + 11790.

Almost surely, 2^31397130 is an apocalyptic number.

31397130 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

31397130 is an abundant number, since it is smaller than the sum of its proper divisors (55041534).

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

31397130 is a wasteful number, since it uses less digits than its factorization.

31397130 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20551 (or 20548 counting only the distinct ones).

The product of its (nonzero) digits is 1701, while the sum is 27.

The square root of 31397130 is about 5603.3141978654. The cubic root of 31397130 is about 315.4738145324.

The spelling of 31397130 in words is "thirty-one million, three hundred ninety-seven thousand, one hundred thirty".