31421985 has 24 divisors (see below), whose sum is σ = 58484736. Its totient is φ = 14364000.

The previous prime is 31421981. The next prime is 31421987. The reversal of 31421985 is 58912413.

It is not a de Polignac number, because 31421985 - 2² = 31421981 is a prime.

It is a super-2 number, since 2×31421985² = 1974682282680450, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (31421981) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 20641 + ... + 22110.

It is an arithmetic number, because the mean of its divisors is an integer number (2436864).

Almost surely, 2^31421985 is an apocalyptic number.

31421985 is a gapful number since it is divisible by the number (35) formed by its first and last digit.

It is an amenable number.

31421985 is a deficient number, since it is larger than the sum of its proper divisors (27062751).

31421985 is a wasteful number, since it uses less digits than its factorization.

31421985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42773 (or 42766 counting only the distinct ones).

The product of its digits is 8640, while the sum is 33.

The square root of 31421985 is about 5605.5316429399. The cubic root of 31421985 is about 315.5570390551.

The spelling of 31421985 in words is "thirty-one million, four hundred twenty-one thousand, nine hundred eighty-five".