621729813 has 16 divisors (see below), whose sum is σ = 873110016. Its totient is φ = 392755440.

The previous prime is 621729809. The next prime is 621729817. The reversal of 621729813 is 318927126.

It is an interprime number because it is at equal distance from previous prime (621729809) and next prime (621729817).

It is not a de Polignac number, because 621729813 - 2² = 621729809 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (621729817) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 34723 + ... + 49488.

It is an arithmetic number, because the mean of its divisors is an integer number (54569376).

Almost surely, 2^621729813 is an apocalyptic number.

It is an amenable number.

621729813 is a deficient number, since it is larger than the sum of its proper divisors (251380203).

621729813 is a wasteful number, since it uses less digits than its factorization.

621729813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84344.

The product of its digits is 36288, while the sum is 39.

The square root of 621729813 is about 24934.5104824619. The cubic root of 621729813 is about 853.4941806814.

The spelling of 621729813 in words is "six hundred twenty-one million, seven hundred twenty-nine thousand, eight hundred thirteen".