31425813 has 10 divisors (see below), whose sum is σ = 46944854. Its totient is φ = 20950488.

The previous prime is 31425799. The next prime is 31425827. The reversal of 31425813 is 31852413.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (31425799) and next prime (31425827).

It can be written as a sum of positive squares in only one way, i.e., 31337604 + 88209 = 5598^2 + 297^2 .

It is not a de Polignac number, because 31425813 - 2⁵ = 31425781 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31425833) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 193906 + ... + 194067.

Almost surely, 2^31425813 is an apocalyptic number.

It is an amenable number.

31425813 is a deficient number, since it is larger than the sum of its proper divisors (15519041).

31425813 is an equidigital number, since it uses as much as digits as its factorization.

31425813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 387985 (or 387976 counting only the distinct ones).

The product of its digits is 2880, while the sum is 27.

The square root of 31425813 is about 5605.8730809750. The cubic root of 31425813 is about 315.5698528360.

The spelling of 31425813 in words is "thirty-one million, four hundred twenty-five thousand, eight hundred thirteen".