77623621 has 2 divisors, whose sum is σ = 77623622. Its totient is φ = 77623620.

The previous prime is 77623613. The next prime is 77623631. The reversal of 77623621 is 12632677.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 71064900 + 6558721 = 8430^2 + 2561^2 .

It is a cyclic number.

It is not a de Polignac number, because 77623621 - 2³ = 77623613 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77623631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38811810 + 38811811.

It is an arithmetic number, because the mean of its divisors is an integer number (38811811).

Almost surely, 2^77623621 is an apocalyptic number.

It is an amenable number.

77623621 is a deficient number, since it is larger than the sum of its proper divisors (1).

77623621 is an equidigital number, since it uses as much as digits as its factorization.

77623621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 21168, while the sum is 34.

The square root of 77623621 is about 8810.4268341551. The cubic root of 77623621 is about 426.5775209128.

The spelling of 77623621 in words is "seventy-seven million, six hundred twenty-three thousand, six hundred twenty-one".