621857633909 has 4 divisors (see below), whose sum is σ = 626604638880. Its totient is φ = 617110628940.

The previous prime is 621857633899. The next prime is 621857633933. The reversal of 621857633909 is 909336758126.

621857633909 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 621857633909 - 2²⁰ = 621856585333 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (621857233909) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2373502289 + ... + 2373502550.

It is an arithmetic number, because the mean of its divisors is an integer number (156651159720).

Almost surely, 2^621857633909 is an apocalyptic number.

It is an amenable number.

621857633909 is a deficient number, since it is larger than the sum of its proper divisors (4747004971).

621857633909 is a wasteful number, since it uses less digits than its factorization.

621857633909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4747004970.

The product of its (nonzero) digits is 14696640, while the sum is 59.

The spelling of 621857633909 in words is "six hundred twenty-one billion, eight hundred fifty-seven million, six hundred thirty-three thousand, nine hundred nine".