21986667081 has 32 divisors (see below), whose sum is σ = 34063223040. Its totient is φ = 13989888000.

The previous prime is 21986667071. The next prime is 21986667083. The reversal of 21986667081 is 18076668912.

It is not a de Polignac number, because 21986667081 - 2⁷ = 21986666953 is a prime.

It is a super-2 number, since 2×21986667081² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21986667083) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 247881 + ... + 324681.

It is an arithmetic number, because the mean of its divisors is an integer number (1064475720).

Almost surely, 2^21986667081 is an apocalyptic number.

It is an amenable number.

21986667081 is a deficient number, since it is larger than the sum of its proper divisors (12076555959).

21986667081 is a wasteful number, since it uses less digits than its factorization.

21986667081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77294 (or 77288 counting only the distinct ones).

The product of its (nonzero) digits is 1741824, while the sum is 54.

The spelling of 21986667081 in words is "twenty-one billion, nine hundred eighty-six million, six hundred sixty-seven thousand, eighty-one".