621043391 has 2 divisors, whose sum is σ = 621043392. Its totient is φ = 621043390.

The previous prime is 621043369. The next prime is 621043403. The reversal of 621043391 is 193340126.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 621043391 - 2¹⁴ = 621027007 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 (621043321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310521695 + 310521696.

It is an arithmetic number, because the mean of its divisors is an integer number (310521696).

Almost surely, 2^621043391 is an apocalyptic number.

621043391 is a deficient number, since it is larger than the sum of its proper divisors (1).

621043391 is an equidigital number, since it uses as much as digits as its factorization.

621043391 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3888, while the sum is 29.

The square root of 621043391 is about 24920.7421839720. The cubic root of 621043391 is about 853.1799643835.

The spelling of 621043391 in words is "six hundred twenty-one million, forty-three thousand, three hundred ninety-one".