31801985 has 16 divisors (see below), whose sum is σ = 42166656. Its totient is φ = 22902528.

The previous prime is 31801969. The next prime is 31802021. The reversal of 31801985 is 58910813.

It is a cyclic number.

It is not a de Polignac number, because 31801985 - 2⁴ = 31801969 is a prime.

It is a super-2 number, since 2×31801985² = 2022732499880450, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6179 + ... + 10088.

It is an arithmetic number, because the mean of its divisors is an integer number (2635416).

Almost surely, 2^31801985 is an apocalyptic number.

It is an amenable number.

31801985 is a deficient number, since it is larger than the sum of its proper divisors (10364671).

31801985 is a wasteful number, since it uses less digits than its factorization.

31801985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16312.

The product of its (nonzero) digits is 8640, while the sum is 35.

The square root of 31801985 is about 5639.3248709398. The cubic root of 31801985 is about 316.8240024550.

The spelling of 31801985 in words is "thirty-one million, eight hundred one thousand, nine hundred eighty-five".