621941657 has 2 divisors, whose sum is σ = 621941658. Its totient is φ = 621941656.

The previous prime is 621941603. The next prime is 621941693. The reversal of 621941657 is 756149126.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 618467161 + 3474496 = 24869^2 + 1864^2 .

It is a cyclic number.

It is not a de Polignac number, because 621941657 - 2¹⁴ = 621925273 is a prime.

It is a super-2 number, since 2×621941657² = 773622849423811298, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (621941557) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310970828 + 310970829.

It is an arithmetic number, because the mean of its divisors is an integer number (310970829).

Almost surely, 2^621941657 is an apocalyptic number.

It is an amenable number.

621941657 is a deficient number, since it is larger than the sum of its proper divisors (1).

621941657 is an equidigital number, since it uses as much as digits as its factorization.

621941657 is an evil number, because the sum of its binary digits is even.

The product of its digits is 90720, while the sum is 41.

The square root of 621941657 is about 24938.7581286639. The cubic root of 621941657 is about 853.5911076131.

The spelling of 621941657 in words is "six hundred twenty-one million, nine hundred forty-one thousand, six hundred fifty-seven".