21551183116 has 12 divisors (see below), whose sum is σ = 37721874960. Its totient is φ = 10773504560.

The previous prime is 21551183081. The next prime is 21551183119. The reversal of 21551183116 is 61138115512.

It is not an unprimeable number, because it can be changed into a prime (21551183119) 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, 498400 + ... + 539911.

It is an arithmetic number, because the mean of its divisors is an integer number (3143489580).

Almost surely, 2^21551183116 is an apocalyptic number.

It is an amenable number.

21551183116 is a deficient number, since it is larger than the sum of its proper divisors (16170691844).

21551183116 is a wasteful number, since it uses less digits than its factorization.

21551183116 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1043504 (or 1043502 counting only the distinct ones).

The product of its digits is 7200, while the sum is 34.

Adding to 21551183116 its reverse (61138115512), we get a palindrome (82689298628).

The spelling of 21551183116 in words is "twenty-one billion, five hundred fifty-one million, one hundred eighty-three thousand, one hundred sixteen".