31423531 has 4 divisors (see below), whose sum is σ = 33271992. Its totient is φ = 29575072.

The previous prime is 31423529. The next prime is 31423573. The reversal of 31423531 is 13532413.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13532413 = 317 ⋅42689.

It is a cyclic number.

It is not a de Polignac number, because 31423531 - 2¹ = 31423529 is a prime.

It is a super-2 number, since 2×31423531² = 1974876601015922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (31423331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 924205 + ... + 924238.

It is an arithmetic number, because the mean of its divisors is an integer number (8317998).

Almost surely, 2^31423531 is an apocalyptic number.

31423531 is a deficient number, since it is larger than the sum of its proper divisors (1848461).

31423531 is a wasteful number, since it uses less digits than its factorization.

31423531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1848460.

The product of its digits is 1080, while the sum is 22.

The square root of 31423531 is about 5605.6695407418. The cubic root of 31423531 is about 315.5622142340.

Adding to 31423531 its reverse (13532413), we get a palindrome (44955944).

The spelling of 31423531 in words is "thirty-one million, four hundred twenty-three thousand, five hundred thirty-one".