31423421 has 2 divisors, whose sum is σ = 31423422. Its totient is φ = 31423420.

The previous prime is 31423391. The next prime is 31423433. The reversal of 31423421 is 12432413.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 31416025 + 7396 = 5605^2 + 86^2 .

It is a cyclic number.

It is not a de Polignac number, because 31423421 - 2¹⁴ = 31407037 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 31423393 and 31423402.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31423621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15711710 + 15711711.

It is an arithmetic number, because the mean of its divisors is an integer number (15711711).

Almost surely, 2^31423421 is an apocalyptic number.

It is an amenable number.

31423421 is a deficient number, since it is larger than the sum of its proper divisors (1).

31423421 is an equidigital number, since it uses as much as digits as its factorization.

31423421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 576, while the sum is 20.

The square root of 31423421 is about 5605.6597292379. The cubic root of 31423421 is about 315.5618460186.

Adding to 31423421 its reverse (12432413), we get a palindrome (43855834).

The spelling of 31423421 in words is "thirty-one million, four hundred twenty-three thousand, four hundred twenty-one".