77563621 has 2 divisors, whose sum is σ = 77563622. Its totient is φ = 77563620.

The previous prime is 77563559. The next prime is 77563627. The reversal of 77563621 is 12636577.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 75446596 + 2117025 = 8686^2 + 1455^2 .

It is a cyclic number.

It is not a de Polignac number, because 77563621 - 2¹⁵ = 77530853 is a prime.

It is a super-2 number, since 2×77563621² = 12032230605263282, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77563627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38781810 + 38781811.

It is an arithmetic number, because the mean of its divisors is an integer number (38781811).

Almost surely, 2^77563621 is an apocalyptic number.

It is an amenable number.

77563621 is a deficient number, since it is larger than the sum of its proper divisors (1).

77563621 is an equidigital number, since it uses as much as digits as its factorization.

77563621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 52920, while the sum is 37.

The square root of 77563621 is about 8807.0211195387. The cubic root of 77563621 is about 426.4675833779.

The spelling of 77563621 in words is "seventy-seven million, five hundred sixty-three thousand, six hundred twenty-one".