21127666225 has 12 divisors (see below), whose sum is σ = 26807570416. Its totient is φ = 16509059280.

The previous prime is 21127666201. The next prime is 21127666229. The reversal of 21127666225 is 52266672112.

It is not a de Polignac number, because 21127666225 - 2⁵ = 21127666193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21127666229) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9825747 + ... + 9827896.

Almost surely, 2^21127666225 is an apocalyptic number.

21127666225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21127666225 is a deficient number, since it is larger than the sum of its proper divisors (5679904191).

21127666225 is a wasteful number, since it uses less digits than its factorization.

21127666225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19653696 (or 19653691 counting only the distinct ones).

The product of its digits is 120960, while the sum is 40.

The spelling of 21127666225 in words is "twenty-one billion, one hundred twenty-seven million, six hundred sixty-six thousand, two hundred twenty-five".