621534391 has 2 divisors, whose sum is σ = 621534392. Its totient is φ = 621534390.

The previous prime is 621534383. The next prime is 621534413. The reversal of 621534391 is 193435126.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 621534391 - 2³ = 621534383 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (621534091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310767195 + 310767196.

It is an arithmetic number, because the mean of its divisors is an integer number (310767196).

Almost surely, 2^621534391 is an apocalyptic number.

621534391 is a deficient number, since it is larger than the sum of its proper divisors (1).

621534391 is an equidigital number, since it uses as much as digits as its factorization.

621534391 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 19440, while the sum is 34.

The square root of 621534391 is about 24930.5914691168. The cubic root of 621534391 is about 853.4047479329.

The spelling of 621534391 in words is "six hundred twenty-one million, five hundred thirty-four thousand, three hundred ninety-one".