20511725 has 12 divisors (see below), whose sum is σ = 27391476. Its totient is φ = 15146880.

The previous prime is 20511713. The next prime is 20511737. The reversal of 20511725 is 52711502.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20511713) and next prime (20511737).

It can be written as a sum of positive squares in 6 ways, for example, as 6056521 + 14455204 = 2461^2 + 3802^2 .

It is not a de Polignac number, because 20511725 - 2⁴ = 20511709 is a prime.

It is a hoax number, since the sum of its digits (23) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20511725.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 31232 + ... + 31881.

It is an arithmetic number, because the mean of its divisors is an integer number (2282623).

Almost surely, 2^20511725 is an apocalyptic number.

20511725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20511725 is a deficient number, since it is larger than the sum of its proper divisors (6879751).

20511725 is a wasteful number, since it uses less digits than its factorization.

20511725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63136 (or 63131 counting only the distinct ones).

The product of its (nonzero) digits is 700, while the sum is 23.

The square root of 20511725 is about 4528.9871936229. The cubic root of 20511725 is about 273.7373519868.

The spelling of 20511725 in words is "twenty million, five hundred eleven thousand, seven hundred twenty-five".