621620999 has 2 divisors, whose sum is σ = 621621000. Its totient is φ = 621620998.

The previous prime is 621620969. The next prime is 621621037. The reversal of 621620999 is 999026126.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 621620999 - 2¹² = 621616903 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (621620939) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310810499 + 310810500.

It is an arithmetic number, because the mean of its divisors is an integer number (310810500).

Almost surely, 2^621620999 is an apocalyptic number.

621620999 is a deficient number, since it is larger than the sum of its proper divisors (1).

621620999 is an equidigital number, since it uses as much as digits as its factorization.

621620999 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 104976, while the sum is 44.

The square root of 621620999 is about 24932.3283910669. The cubic root of 621620999 is about 853.4443854529. Note that the first 3 decimals are identical.

The spelling of 621620999 in words is "six hundred twenty-one million, six hundred twenty thousand, nine hundred ninety-nine".