31426921 has 4 divisors (see below), whose sum is σ = 31508100. Its totient is φ = 31345744.

The previous prime is 31426919. The next prime is 31426939. The reversal of 31426921 is 12962413.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12962413 = 359 ⋅36107.

It can be written as a sum of positive squares in 2 ways, for example, as 5017600 + 26409321 = 2240^2 + 5139^2 .

It is a cyclic number.

It is not a de Polignac number, because 31426921 - 2¹ = 31426919 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 31426921.

It is not an unprimeable number, because it can be changed into a prime (31423921) 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, 40006 + ... + 40783.

It is an arithmetic number, because the mean of its divisors is an integer number (7877025).

Almost surely, 2^31426921 is an apocalyptic number.

It is an amenable number.

31426921 is a deficient number, since it is larger than the sum of its proper divisors (81179).

31426921 is an equidigital number, since it uses as much as digits as its factorization.

31426921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81178.

The product of its digits is 2592, while the sum is 28.

The square root of 31426921 is about 5605.9719050313. The cubic root of 31426921 is about 315.5735615419.

The spelling of 31426921 in words is "thirty-one million, four hundred twenty-six thousand, nine hundred twenty-one".