31623409 has 4 divisors (see below), whose sum is σ = 31719280. Its totient is φ = 31527540.

The previous prime is 31623377. The next prime is 31623421. The reversal of 31623409 is 90432613.

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: 90432613 = 109 ⋅829657.

It is a cyclic number.

It is not a de Polignac number, because 31623409 - 2⁵ = 31623377 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31623439) 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, 47439 + ... + 48100.

It is an arithmetic number, because the mean of its divisors is an integer number (7929820).

Almost surely, 2^31623409 is an apocalyptic number.

It is an amenable number.

31623409 is a deficient number, since it is larger than the sum of its proper divisors (95871).

31623409 is an equidigital number, since it uses as much as digits as its factorization.

31623409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95870.

The product of its (nonzero) digits is 3888, while the sum is 28.

The square root of 31623409 is about 5623.4694806676. The cubic root of 31623409 is about 316.2298739972.

The spelling of 31623409 in words is "thirty-one million, six hundred twenty-three thousand, four hundred nine".