31409621 has 2 divisors, whose sum is σ = 31409622. Its totient is φ = 31409620.

The previous prime is 31409617. The next prime is 31409627. The reversal of 31409621 is 12690413.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 30747025 + 662596 = 5545^2 + 814^2 .

It is a cyclic number.

It is not a de Polignac number, because 31409621 - 2² = 31409617 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31409627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15704810 + 15704811.

It is an arithmetic number, because the mean of its divisors is an integer number (15704811).

Almost surely, 2^31409621 is an apocalyptic number.

It is an amenable number.

31409621 is a deficient number, since it is larger than the sum of its proper divisors (1).

31409621 is an equidigital number, since it uses as much as digits as its factorization.

31409621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 31409621 is about 5604.4286952374. The cubic root of 31409621 is about 315.5156449052.

The spelling of 31409621 in words is "thirty-one million, four hundred nine thousand, six hundred twenty-one".