621656099 has 2 divisors, whose sum is σ = 621656100. Its totient is φ = 621656098.

The previous prime is 621656023. The next prime is 621656107. The reversal of 621656099 is 990656126.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-621656099 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (621656899) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310828049 + 310828050.

It is an arithmetic number, because the mean of its divisors is an integer number (310828050).

Almost surely, 2^621656099 is an apocalyptic number.

621656099 is a deficient number, since it is larger than the sum of its proper divisors (1).

621656099 is an equidigital number, since it uses as much as digits as its factorization.

621656099 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 174960, while the sum is 44.

The square root of 621656099 is about 24933.0322865070. The cubic root of 621656099 is about 853.4604484742.

The spelling of 621656099 in words is "six hundred twenty-one million, six hundred fifty-six thousand, ninety-nine".