21616611859 has 6 divisors (see below), whose sum is σ = 21674860116. Its totient is φ = 21558519720.

The previous prime is 21616611857. The next prime is 21616611901. The reversal of 21616611859 is 95811661612.

It is not a de Polignac number, because 21616611859 - 2¹ = 21616611857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21616611857) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 61444 + ... + 216814.

It is an arithmetic number, because the mean of its divisors is an integer number (3612476686).

Almost surely, 2^21616611859 is an apocalyptic number.

21616611859 is a deficient number, since it is larger than the sum of its proper divisors (58248257).

21616611859 is an frugal number, since it uses more digits than its factorization.

21616611859 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156117 (or 155744 counting only the distinct ones).

The product of its digits is 155520, while the sum is 46.

The spelling of 21616611859 in words is "twenty-one billion, six hundred sixteen million, six hundred eleven thousand, eight hundred fifty-nine".