21377619081 has 48 divisors (see below), whose sum is σ = 38525375616. Its totient is φ = 11121608448.

The previous prime is 21377619061. The next prime is 21377619083. The reversal of 21377619081 is 18091677312.

21377619081 is a `hidden beast` number, since 21 + 3 + 7 + 7 + 619 + 0 + 8 + 1 = 666.

It is not a de Polignac number, because 21377619081 - 2¹⁷ = 21377488009 is a prime.

It is a super-2 number, since 2×21377619081² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21377619083) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 118995 + ... + 238568.

It is an arithmetic number, because the mean of its divisors is an integer number (802611992).

Almost surely, 2^21377619081 is an apocalyptic number.

21377619081 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21377619081 is a deficient number, since it is larger than the sum of its proper divisors (17147756535).

21377619081 is a wasteful number, since it uses less digits than its factorization.

21377619081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 357662 (or 357659 counting only the distinct ones).

The product of its (nonzero) digits is 127008, while the sum is 45.

The spelling of 21377619081 in words is "twenty-one billion, three hundred seventy-seven million, six hundred nineteen thousand, eighty-one".