99621001 has 2 divisors, whose sum is σ = 99621002. Its totient is φ = 99621000.

The previous prime is 99620987. The next prime is 99621007. The reversal of 99621001 is 10012699.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 80084601 + 19536400 = 8949^2 + 4420^2 .

It is an emirp because it is prime and its reverse (10012699) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 99621001 - 2⁹ = 99620489 is a prime.

It is not a weakly prime, because it can be changed into another prime (99621007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49810500 + 49810501.

It is an arithmetic number, because the mean of its divisors is an integer number (49810501).

Almost surely, 2^99621001 is an apocalyptic number.

It is an amenable number.

99621001 is a deficient number, since it is larger than the sum of its proper divisors (1).

99621001 is an equidigital number, since it uses as much as digits as its factorization.

99621001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 972, while the sum is 28.

The square root of 99621001 is about 9981.0320608642. The cubic root of 99621001 is about 463.5717551566.

The spelling of 99621001 in words is "ninety-nine million, six hundred twenty-one thousand, one".