31475621 has 4 divisors (see below), whose sum is σ = 31511232. Its totient is φ = 31440012.

The previous prime is 31475611. The next prime is 31475623. The reversal of 31475621 is 12657413.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12657413 = 659 ⋅19207.

It is a cyclic number.

It is not a de Polignac number, because 31475621 - 2¹⁸ = 31213477 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31475623) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16445 + ... + 18258.

It is an arithmetic number, because the mean of its divisors is an integer number (7877808).

Almost surely, 2^31475621 is an apocalyptic number.

It is an amenable number.

31475621 is a deficient number, since it is larger than the sum of its proper divisors (35611).

31475621 is an equidigital number, since it uses as much as digits as its factorization.

31475621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35610.

The product of its digits is 5040, while the sum is 29.

The square root of 31475621 is about 5610.3138058401. The cubic root of 31475621 is about 315.7364845003.

The spelling of 31475621 in words is "thirty-one million, four hundred seventy-five thousand, six hundred twenty-one".