25221666775 has 12 divisors (see below), whose sum is σ = 31303255392. Its totient is φ = 20159018240.

The previous prime is 25221666731. The next prime is 25221666781. The reversal of 25221666775 is 57766612252.

It is a de Polignac number, because none of the positive numbers 2^k-25221666775 is a prime.

It is a super-2 number, since 2×25221666775² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 429754 + ... + 484903.

It is an arithmetic number, because the mean of its divisors is an integer number (2608604616).

Almost surely, 2^25221666775 is an apocalyptic number.

25221666775 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

25221666775 is a deficient number, since it is larger than the sum of its proper divisors (6081588617).

25221666775 is a wasteful number, since it uses less digits than its factorization.

25221666775 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 915770 (or 915765 counting only the distinct ones).

The product of its digits is 2116800, while the sum is 49.

The spelling of 25221666775 in words is "twenty-five billion, two hundred twenty-one million, six hundred sixty-six thousand, seven hundred seventy-five".