1621642724556 has 24 divisors (see below), whose sum is σ = 3784256474544. Its totient is φ = 540487081920.

The previous prime is 1621642724509. The next prime is 1621642724557. The reversal of 1621642724556 is 6554272461261.

It is a super-2 number, since 2×1621642724556² (a number of 25 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1621642724499 and 1621642724508.

It is not an unprimeable number, because it can be changed into a prime (1621642724557) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7449855 + ... + 7664438.

It is an arithmetic number, because the mean of its divisors is an integer number (157677353106).

Almost surely, 2^{1621642724556} is an apocalyptic number.

It is an amenable number.

1621642724556 is an abundant number, since it is smaller than the sum of its proper divisors (2162613749988).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1621642724556 is a wasteful number, since it uses less digits than its factorization.

1621642724556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15123241 (or 15123239 counting only the distinct ones).

The product of its digits is 4838400, while the sum is 51.

The spelling of 1621642724556 in words is "one trillion, six hundred twenty-one billion, six hundred forty-two million, seven hundred twenty-four thousand, five hundred fifty-six".