31789421 has 2 divisors, whose sum is σ = 31789422. Its totient is φ = 31789420.

The previous prime is 31789411. The next prime is 31789463. The reversal of 31789421 is 12498713.

31789421 is nontrivially palindromic in base 4.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 22705225 + 9084196 = 4765^2 + 3014^2 .

It is a cyclic number.

It is not a de Polignac number, because 31789421 - 2¹⁸ = 31527277 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31789411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15894710 + 15894711.

It is an arithmetic number, because the mean of its divisors is an integer number (15894711).

Almost surely, 2^31789421 is an apocalyptic number.

It is an amenable number.

31789421 is a deficient number, since it is larger than the sum of its proper divisors (1).

31789421 is an equidigital number, since it uses as much as digits as its factorization.

31789421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12096, while the sum is 35.

The square root of 31789421 is about 5638.2107977620. The cubic root of 31789421 is about 316.7822744404.

The spelling of 31789421 in words is "thirty-one million, seven hundred eighty-nine thousand, four hundred twenty-one".