21555485774 has 8 divisors (see below), whose sum is σ = 32367159360. Its totient is φ = 10766432656.

The previous prime is 21555485753. The next prime is 21555485813. The reversal of 21555485774 is 47758455512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5652734 + ... + 5656545.

It is an arithmetic number, because the mean of its divisors is an integer number (4045894920).

Almost surely, 2^21555485774 is an apocalyptic number.

21555485774 is a deficient number, since it is larger than the sum of its proper divisors (10811673586).

21555485774 is a wasteful number, since it uses less digits than its factorization.

21555485774 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11310234.

The product of its digits is 7840000, while the sum is 53.

The spelling of 21555485774 in words is "twenty-one billion, five hundred fifty-five million, four hundred eighty-five thousand, seven hundred seventy-four".