621993403 has 2 divisors, whose sum is σ = 621993404. Its totient is φ = 621993402.

The previous prime is 621993401. The next prime is 621993473. The reversal of 621993403 is 304399126.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 621993403 - 2¹ = 621993401 is a prime.

Together with 621993401, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (621993401) 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, 310996701 + 310996702.

It is an arithmetic number, because the mean of its divisors is an integer number (310996702).

Almost surely, 2^621993403 is an apocalyptic number.

621993403 is a deficient number, since it is larger than the sum of its proper divisors (1).

621993403 is an equidigital number, since it uses as much as digits as its factorization.

621993403 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 34992, while the sum is 37.

The square root of 621993403 is about 24939.7955685286. The cubic root of 621993403 is about 853.6147800911.

The spelling of 621993403 in words is "six hundred twenty-one million, nine hundred ninety-three thousand, four hundred three".