20665734225 has 96 divisors (see below), whose sum is σ = 37537240320. Its totient is φ = 9985597440.

The previous prime is 20665734113. The next prime is 20665734239. The reversal of 20665734225 is 52243756602.

It is a happy number.

It is not a de Polignac number, because 20665734225 - 2⁷ = 20665734097 is a prime.

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, 16896964 + ... + 16898186.

It is an arithmetic number, because the mean of its divisors is an integer number (391012920).

Almost surely, 2^20665734225 is an apocalyptic number.

20665734225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20665734225 is a deficient number, since it is larger than the sum of its proper divisors (16871506095).

20665734225 is a wasteful number, since it uses less digits than its factorization.

20665734225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1739 (or 1734 counting only the distinct ones).

The product of its (nonzero) digits is 604800, while the sum is 42.

The spelling of 20665734225 in words is "twenty billion, six hundred sixty-five million, seven hundred thirty-four thousand, two hundred twenty-five".