31425921 has 8 divisors (see below), whose sum is σ = 46556960. Its totient is φ = 20950596.

The previous prime is 31425917. The next prime is 31425929. The reversal of 31425921 is 12952413.

31425921 is a `hidden beast` number, since 31 + 42 + 592 + 1 = 666.

It is not a de Polignac number, because 31425921 - 2² = 31425917 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 1163923 = 31425921 / (3 + 1 + 4 + 2 + 5 + 9 + 2 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31425929) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 581935 + ... + 581988.

It is an arithmetic number, because the mean of its divisors is an integer number (5819620).

Almost surely, 2^31425921 is an apocalyptic number.

It is an amenable number.

31425921 is a deficient number, since it is larger than the sum of its proper divisors (15131039).

31425921 is a wasteful number, since it uses less digits than its factorization.

31425921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1163932 (or 1163926 counting only the distinct ones).

The product of its digits is 2160, while the sum is 27.

The square root of 31425921 is about 5605.8827137214. The cubic root of 31425921 is about 315.5702143383.

The spelling of 31425921 in words is "thirty-one million, four hundred twenty-five thousand, nine hundred twenty-one".