31601661 has 16 divisors (see below), whose sum is σ = 51859584. Its totient is φ = 16668864.

The previous prime is 31601651. The next prime is 31601671. The reversal of 31601661 is 16610613.

It is an interprime number because it is at equal distance from previous prime (31601651) and next prime (31601671).

It is not a de Polignac number, because 31601661 - 2⁵ = 31601629 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31601651) 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, 57606 + ... + 58151.

It is an arithmetic number, because the mean of its divisors is an integer number (3241224).

Almost surely, 2^31601661 is an apocalyptic number.

It is an amenable number.

31601661 is a deficient number, since it is larger than the sum of its proper divisors (20257923).

31601661 is a wasteful number, since it uses less digits than its factorization.

31601661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115780.

The product of its (nonzero) digits is 648, while the sum is 24.

The square root of 31601661 is about 5621.5354664006. The cubic root of 31601661 is about 316.1573650059.

The spelling of 31601661 in words is "thirty-one million, six hundred one thousand, six hundred sixty-one".