21881571396 has 12 divisors (see below), whose sum is σ = 51056999952. Its totient is φ = 7293857128.

The previous prime is 21881571353. The next prime is 21881571461. The reversal of 21881571396 is 69317518812.

It is a tau number, because it is divible by the number of its divisors (12).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 911732130 + ... + 911732153.

It is an arithmetic number, because the mean of its divisors is an integer number (4254749996).

Almost surely, 2^21881571396 is an apocalyptic number.

It is an amenable number.

21881571396 is an abundant number, since it is smaller than the sum of its proper divisors (29175428556).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21881571396 is a wasteful number, since it uses less digits than its factorization.

21881571396 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1823464290 (or 1823464288 counting only the distinct ones).

The product of its digits is 725760, while the sum is 51.

The spelling of 21881571396 in words is "twenty-one billion, eight hundred eighty-one million, five hundred seventy-one thousand, three hundred ninety-six".