621981461 has 2 divisors, whose sum is σ = 621981462. Its totient is φ = 621981460.

The previous prime is 621981449. The next prime is 621981467. The reversal of 621981461 is 164189126.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 408646225 + 213335236 = 20215^2 + 14606^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-621981461 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (621981467) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310990730 + 310990731.

It is an arithmetic number, because the mean of its divisors is an integer number (310990731).

Almost surely, 2^621981461 is an apocalyptic number.

It is an amenable number.

621981461 is a deficient number, since it is larger than the sum of its proper divisors (1).

621981461 is an equidigital number, since it uses as much as digits as its factorization.

621981461 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20736, while the sum is 38.

The square root of 621981461 is about 24939.5561508219. The cubic root of 621981461 is about 853.6093170466.

The spelling of 621981461 in words is "six hundred twenty-one million, nine hundred eighty-one thousand, four hundred sixty-one".