20666025 has 36 divisors (see below), whose sum is σ = 37735308. Its totient is φ = 10807680.

The previous prime is 20666021. The next prime is 20666047. The reversal of 20666025 is 52066602.

It can be written as a sum of positive squares in 6 ways, for example, as 63504 + 20602521 = 252^2 + 4539^2 .

It is not a de Polignac number, because 20666025 - 2² = 20666021 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 20666025.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20666021) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 11059 + ... + 12791.

It is an arithmetic number, because the mean of its divisors is an integer number (1048203).

Almost surely, 2^20666025 is an apocalyptic number.

20666025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20666025 is a deficient number, since it is larger than the sum of its proper divisors (17069283).

20666025 is a wasteful number, since it uses less digits than its factorization.

20666025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1802 (or 1794 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 20666025 is about 4545.9899911900. The cubic root of 20666025 is about 274.4220368436.

The spelling of 20666025 in words is "twenty million, six hundred sixty-six thousand, twenty-five".