7931621 has 2 divisors, whose sum is σ = 7931622. Its totient is φ = 7931620.

The previous prime is 7931611. The next prime is 7931633. The reversal of 7931621 is 1261397.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7924225 + 7396 = 2815^2 + 86^2 .

It is a cyclic number.

It is not a de Polignac number, because 7931621 - 2¹⁰ = 7930597 is a prime.

It is a super-2 number, since 2×7931621² = 125821223375282, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7931611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3965810 + 3965811.

It is an arithmetic number, because the mean of its divisors is an integer number (3965811).

Almost surely, 2^7931621 is an apocalyptic number.

It is an amenable number.

7931621 is a deficient number, since it is larger than the sum of its proper divisors (1).

7931621 is an equidigital number, since it uses as much as digits as its factorization.

7931621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2268, while the sum is 29.

The square root of 7931621 is about 2816.3133703478. The cubic root of 7931621 is about 199.4285437439.

The spelling of 7931621 in words is "seven million, nine hundred thirty-one thousand, six hundred twenty-one".