621764421623 has 4 divisors (see below), whose sum is σ = 624432938688. Its totient is φ = 619095904560.

The previous prime is 621764421611. The next prime is 621764421647. The reversal of 621764421623 is 326124467126.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 621764421623 - 2²⁰ = 621763373047 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 (621764429623) 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, 1334258183 + ... + 1334258648.

It is an arithmetic number, because the mean of its divisors is an integer number (156108234672).

Almost surely, 2^621764421623 is an apocalyptic number.

621764421623 is a deficient number, since it is larger than the sum of its proper divisors (2668517065).

621764421623 is a wasteful number, since it uses less digits than its factorization.

621764421623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2668517064.

The product of its digits is 580608, while the sum is 44.

Adding to 621764421623 its reverse (326124467126), we get a palindrome (947888888749).

The spelling of 621764421623 in words is "six hundred twenty-one billion, seven hundred sixty-four million, four hundred twenty-one thousand, six hundred twenty-three".