21279266225 has 24 divisors (see below), whose sum is σ = 30580507008. Its totient is φ = 14385974400.

The previous prime is 21279266219. The next prime is 21279266237. The reversal of 21279266225 is 52266297212.

It is not a de Polignac number, because 21279266225 - 2¹⁰ = 21279265201 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 843884 + ... + 868733.

It is an arithmetic number, because the mean of its divisors is an integer number (1274187792).

Almost surely, 2^21279266225 is an apocalyptic number.

21279266225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21279266225 is a deficient number, since it is larger than the sum of its proper divisors (9301240783).

21279266225 is a wasteful number, since it uses less digits than its factorization.

21279266225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1712705 (or 1712700 counting only the distinct ones).

The product of its digits is 362880, while the sum is 44.

The spelling of 21279266225 in words is "twenty-one billion, two hundred seventy-nine million, two hundred sixty-six thousand, two hundred twenty-five".