872556621421 has 4 divisors (see below), whose sum is σ = 872560075132. Its totient is φ = 872553167712.

The previous prime is 872556621401. The next prime is 872556621437. The reversal of 872556621421 is 124126655278.

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

It can be written as a sum of positive squares in 2 ways, for example, as 362169258025 + 510387363396 = 601805^2 + 714414^2 .

It is a cyclic number.

It is not a de Polignac number, because 872556621421 - 2⁵ = 872556621389 is a prime.

It is a super-2 number, since 2×872556621421² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (872556621401) 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, 1315176 + ... + 1864081.

It is an arithmetic number, because the mean of its divisors is an integer number (218140018783).

Almost surely, 2^872556621421 is an apocalyptic number.

It is an amenable number.

872556621421 is a deficient number, since it is larger than the sum of its proper divisors (3453711).

872556621421 is a wasteful number, since it uses less digits than its factorization.

872556621421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3453710.

The product of its digits is 1612800, while the sum is 49.

The spelling of 872556621421 in words is "eight hundred seventy-two billion, five hundred fifty-six million, six hundred twenty-one thousand, four hundred twenty-one".