621136669 has 2 divisors, whose sum is σ = 621136670. Its totient is φ = 621136668.

The previous prime is 621136639. The next prime is 621136673. The reversal of 621136669 is 966631126.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 352012644 + 269124025 = 18762^2 + 16405^2 .

It is a cyclic number.

It is not a de Polignac number, because 621136669 - 2²¹ = 619039517 is a prime.

It is a super-2 number, since 2×621136669² = 771621523152831122, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (621136639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310568334 + 310568335.

It is an arithmetic number, because the mean of its divisors is an integer number (310568335).

Almost surely, 2^621136669 is an apocalyptic number.

It is an amenable number.

621136669 is a deficient number, since it is larger than the sum of its proper divisors (1).

621136669 is an equidigital number, since it uses as much as digits as its factorization.

621136669 is an evil number, because the sum of its binary digits is even.

The product of its digits is 69984, while the sum is 40.

The square root of 621136669 is about 24922.6136069233. The cubic root of 621136669 is about 853.2226768777. Note that the first 3 decimals are identical.

The spelling of 621136669 in words is "six hundred twenty-one million, one hundred thirty-six thousand, six hundred sixty-nine".