621564131 has 2 divisors, whose sum is σ = 621564132. Its totient is φ = 621564130.

The previous prime is 621564091. The next prime is 621564137. The reversal of 621564131 is 131465126.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-621564131 is a prime.

It is a super-2 number, since 2×621564131² = 772683937891570322, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 621564094 and 621564103.

It is not a weakly prime, because it can be changed into another prime (621564137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310782065 + 310782066.

It is an arithmetic number, because the mean of its divisors is an integer number (310782066).

Almost surely, 2^621564131 is an apocalyptic number.

621564131 is a deficient number, since it is larger than the sum of its proper divisors (1).

621564131 is an equidigital number, since it uses as much as digits as its factorization.

621564131 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4320, while the sum is 29.

The square root of 621564131 is about 24931.1879179473. The cubic root of 621564131 is about 853.4183593290.

The spelling of 621564131 in words is "six hundred twenty-one million, five hundred sixty-four thousand, one hundred thirty-one".