313981621 has 2 divisors, whose sum is σ = 313981622. Its totient is φ = 313981620.

The previous prime is 313981607. The next prime is 313981639. The reversal of 313981621 is 126189313.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 187306596 + 126675025 = 13686^2 + 11255^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-313981621 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (313981691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 156990810 + 156990811.

It is an arithmetic number, because the mean of its divisors is an integer number (156990811).

Almost surely, 2^313981621 is an apocalyptic number.

It is an amenable number.

313981621 is a deficient number, since it is larger than the sum of its proper divisors (1).

313981621 is an equidigital number, since it uses as much as digits as its factorization.

313981621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7776, while the sum is 34.

The square root of 313981621 is about 17719.5265455937. The cubic root of 313981621 is about 679.6751771873.

The spelling of 313981621 in words is "three hundred thirteen million, nine hundred eighty-one thousand, six hundred twenty-one".