621163821 has 4 divisors (see below), whose sum is σ = 828218432. Its totient is φ = 414109212.

The previous prime is 621163801. The next prime is 621163849. The reversal of 621163821 is 128361126.

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 not a de Polignac number, because 621163821 - 2¹⁵ = 621131053 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 (621163801) 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 3 ways as a sum of consecutive naturals, for example, 103527301 + ... + 103527306.

It is an arithmetic number, because the mean of its divisors is an integer number (207054608).

Almost surely, 2^621163821 is an apocalyptic number.

It is an amenable number.

621163821 is a deficient number, since it is larger than the sum of its proper divisors (207054611).

621163821 is a wasteful number, since it uses less digits than its factorization.

621163821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 207054610.

The product of its digits is 3456, while the sum is 30.

The square root of 621163821 is about 24923.1583271463. The cubic root of 621163821 is about 853.2351091199.

The spelling of 621163821 in words is "six hundred twenty-one million, one hundred sixty-three thousand, eight hundred twenty-one".