621759491 has 2 divisors, whose sum is σ = 621759492. Its totient is φ = 621759490.

The previous prime is 621759487. The next prime is 621759497. The reversal of 621759491 is 194957126.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 621759491 - 2² = 621759487 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (621759497) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310879745 + 310879746.

It is an arithmetic number, because the mean of its divisors is an integer number (310879746).

Almost surely, 2^621759491 is an apocalyptic number.

621759491 is a deficient number, since it is larger than the sum of its proper divisors (1).

621759491 is an equidigital number, since it uses as much as digits as its factorization.

621759491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 136080, while the sum is 44.

The square root of 621759491 is about 24935.1055943222. The cubic root of 621759491 is about 853.5077608555.

The spelling of 621759491 in words is "six hundred twenty-one million, seven hundred fifty-nine thousand, four hundred ninety-one".