718621 has 2 divisors, whose sum is σ = 718622. Its totient is φ = 718620.

The previous prime is 718603. The next prime is 718633. The reversal of 718621 is 126817.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 622521 + 96100 = 789^2 + 310^2 .

It is a cyclic number.

It is not a de Polignac number, because 718621 - 2⁷ = 718493 is a prime.

It is a super-2 number, since 2×718621² = 1032832283282, which contains 22 as substring.

It is equal to p₅₇₉₃₁ and since 718621 and 57931 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (718661) 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, 359310 + 359311.

It is an arithmetic number, because the mean of its divisors is an integer number (359311).

2⁷¹⁸⁶²¹ is an apocalyptic number.

It is an amenable number.

718621 is a deficient number, since it is larger than the sum of its proper divisors (1).

718621 is an equidigital number, since it uses as much as digits as its factorization.

718621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 672, while the sum is 25.

The square root of 718621 is about 847.7151644273. The cubic root of 718621 is about 89.5708374614.

The spelling of 718621 in words is "seven hundred eighteen thousand, six hundred twenty-one".