21481177188 has 12 divisors (see below), whose sum is σ = 50122746800. Its totient is φ = 7160392392.

The previous prime is 21481177183. The next prime is 21481177213. The reversal of 21481177188 is 88177118412.

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

It is a super-2 number, since 2×21481177188² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21481177183) 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, 895049038 + ... + 895049061.

Almost surely, 2^21481177188 is an apocalyptic number.

It is an amenable number.

21481177188 is an abundant number, since it is smaller than the sum of its proper divisors (28641569612).

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

21481177188 is a wasteful number, since it uses less digits than its factorization.

21481177188 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1790098106 (or 1790098104 counting only the distinct ones).

The product of its digits is 200704, while the sum is 48.

The spelling of 21481177188 in words is "twenty-one billion, four hundred eighty-one million, one hundred seventy-seven thousand, one hundred eighty-eight".