21173526225 has 96 divisors (see below), whose sum is σ = 40390272000. Its totient is φ = 10863244800.

The previous prime is 21173526191. The next prime is 21173526259. The reversal of 21173526225 is 52262537112.

21173526225 is a `hidden beast` number, since 21 + 1 + 7 + 3 + 5 + 2 + 622 + 5 = 666.

It is an interprime number because it is at equal distance from previous prime (21173526191) and next prime (21173526259).

It is not a de Polignac number, because 21173526225 - 2⁶ = 21173526161 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21173526225.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 3617101 + ... + 3622949.

It is an arithmetic number, because the mean of its divisors is an integer number (420732000).

Almost surely, 2^21173526225 is an apocalyptic number.

21173526225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21173526225 is a deficient number, since it is larger than the sum of its proper divisors (19216745775).

21173526225 is a wasteful number, since it uses less digits than its factorization.

21173526225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6072 (or 6061 counting only the distinct ones).

The product of its digits is 50400, while the sum is 36.

The spelling of 21173526225 in words is "twenty-one billion, one hundred seventy-three million, five hundred twenty-six thousand, two hundred twenty-five".