31421431 has 2 divisors, whose sum is σ = 31421432. Its totient is φ = 31421430.

The previous prime is 31421417. The next prime is 31421437. The reversal of 31421431 is 13412413.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 31421431 - 2¹⁵ = 31388663 is a prime.

It is a super-2 number, since 2×31421431² = 1974612652175522, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 31421399 and 31421408.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31421437) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15710715 + 15710716.

It is an arithmetic number, because the mean of its divisors is an integer number (15710716).

Almost surely, 2^31421431 is an apocalyptic number.

31421431 is a deficient number, since it is larger than the sum of its proper divisors (1).

31421431 is an equidigital number, since it uses as much as digits as its factorization.

31421431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 288, while the sum is 19.

The square root of 31421431 is about 5605.4822272486. The cubic root of 31421431 is about 315.5551845189. Note that the first 3 decimals are identical.

Adding to 31421431 its reverse (13412413), we get a palindrome (44833844).

The spelling of 31421431 in words is "thirty-one million, four hundred twenty-one thousand, four hundred thirty-one".