31603661 has 16 divisors (see below), whose sum is σ = 33784128. Its totient is φ = 29520000.

The previous prime is 31603657. The next prime is 31603681. The reversal of 31603661 is 16630613.

It is not a de Polignac number, because 31603661 - 2² = 31603657 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 31603661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31603681) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 125786 + ... + 126036.

It is an arithmetic number, because the mean of its divisors is an integer number (2111508).

Almost surely, 2^31603661 is an apocalyptic number.

It is an amenable number.

31603661 is a deficient number, since it is larger than the sum of its proper divisors (2180467).

31603661 is a wasteful number, since it uses less digits than its factorization.

31603661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 412.

The product of its (nonzero) digits is 1944, while the sum is 26.

The square root of 31603661 is about 5621.7133509278. The cubic root of 31603661 is about 316.1640345012.

The spelling of 31603661 in words is "thirty-one million, six hundred three thousand, six hundred sixty-one".