99977621 has 2 divisors, whose sum is σ = 99977622. Its totient is φ = 99977620.

The previous prime is 99977617. The next prime is 99977627. The reversal of 99977621 is 12677999.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 93876721 + 6100900 = 9689^2 + 2470^2 .

It is a cyclic number.

It is not a de Polignac number, because 99977621 - 2² = 99977617 is a prime.

It is a Chen prime.

It is a nialpdrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 99977621.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (99977627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49988810 + 49988811.

It is an arithmetic number, because the mean of its divisors is an integer number (49988811).

Almost surely, 2^99977621 is an apocalyptic number.

It is an amenable number.

99977621 is a deficient number, since it is larger than the sum of its proper divisors (1).

99977621 is an equidigital number, since it uses as much as digits as its factorization.

99977621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 428652, while the sum is 50.

The square root of 99977621 is about 9998.8809873905. The cubic root of 99977621 is about 464.1242560726.

The spelling of 99977621 in words is "ninety-nine million, nine hundred seventy-seven thousand, six hundred twenty-one".