31242605 has 4 divisors (see below), whose sum is σ = 37491132. Its totient is φ = 24994080.

The previous prime is 31242587. The next prime is 31242619. The reversal of 31242605 is 50624213.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50624213 = 167 ⋅303139.

It can be written as a sum of positive squares in 2 ways, for example, as 17322244 + 13920361 = 4162^2 + 3731^2 .

It is not a de Polignac number, because 31242605 - 2²⁰ = 30194029 is a prime.

It is a super-2 number, since 2×31242605² = 1952200734372050, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3124256 + ... + 3124265.

It is an arithmetic number, because the mean of its divisors is an integer number (9372783).

Almost surely, 2^31242605 is an apocalyptic number.

It is an amenable number.

31242605 is a deficient number, since it is larger than the sum of its proper divisors (6248527).

31242605 is an equidigital number, since it uses as much as digits as its factorization.

31242605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6248526.

The product of its (nonzero) digits is 1440, while the sum is 23.

The square root of 31242605 is about 5589.5084757070. The cubic root of 31242605 is about 314.9554148705.

Adding to 31242605 its reverse (50624213), we get a palindrome (81866818).

It can be divided in two parts, 3 and 1242605, that multiplied together give a triangular number (3727815 = T₂₇₃₀).

The spelling of 31242605 in words is "thirty-one million, two hundred forty-two thousand, six hundred five".