621648331 has 2 divisors, whose sum is σ = 621648332. Its totient is φ = 621648330.

The previous prime is 621648329. The next prime is 621648341. The reversal of 621648331 is 133846126.

It is a happy number.

621648331 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 621648331 - 2¹ = 621648329 is a prime.

It is a super-2 number, since 2×621648331² = 772893294870171122, which contains 22 as substring.

Together with 621648329, it forms a pair of twin primes.

It is equal to p_32394805 and since 621648331 and 32394805 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (621648341) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310824165 + 310824166.

It is an arithmetic number, because the mean of its divisors is an integer number (310824166).

Almost surely, 2^621648331 is an apocalyptic number.

621648331 is a deficient number, since it is larger than the sum of its proper divisors (1).

621648331 is an equidigital number, since it uses as much as digits as its factorization.

621648331 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20736, while the sum is 34.

The square root of 621648331 is about 24932.8765087384. The cubic root of 621648331 is about 853.4568936104.

The spelling of 621648331 in words is "six hundred twenty-one million, six hundred forty-eight thousand, three hundred thirty-one".