78808621 has 2 divisors, whose sum is σ = 78808622. Its totient is φ = 78808620.

The previous prime is 78808607. The next prime is 78808627. The reversal of 78808621 is 12680887.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 54552996 + 24255625 = 7386^2 + 4925^2 .

It is a cyclic number.

It is not a de Polignac number, because 78808621 - 2¹⁹ = 78284333 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 (78808627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39404310 + 39404311.

It is an arithmetic number, because the mean of its divisors is an integer number (39404311).

Almost surely, 2^78808621 is an apocalyptic number.

It is an amenable number.

78808621 is a deficient number, since it is larger than the sum of its proper divisors (1).

78808621 is an equidigital number, since it uses as much as digits as its factorization.

78808621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 43008, while the sum is 40.

The square root of 78808621 is about 8877.4219793812. The cubic root of 78808621 is about 428.7372744539.

The spelling of 78808621 in words is "seventy-eight million, eight hundred eight thousand, six hundred twenty-one".