21055660347 has 8 divisors (see below), whose sum is σ = 28075507200. Its totient is φ = 14036460200.

The previous prime is 21055660313. The next prime is 21055660349. The reversal of 21055660347 is 74306655012.

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

It is a cyclic number.

It is not a de Polignac number, because 21055660347 - 2²⁰ = 21054611771 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21055660349) 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, 79779 + ... + 220172.

It is an arithmetic number, because the mean of its divisors is an integer number (3509438400).

Almost surely, 2^21055660347 is an apocalyptic number.

21055660347 is a deficient number, since it is larger than the sum of its proper divisors (7019846853).

21055660347 is a wasteful number, since it uses less digits than its factorization.

21055660347 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 323353.

The product of its (nonzero) digits is 151200, while the sum is 39.

The spelling of 21055660347 in words is "twenty-one billion, fifty-five million, six hundred sixty thousand, three hundred forty-seven".