20765251 has 16 divisors (see below), whose sum is σ = 23978304. Its totient is φ = 17829504.

The previous prime is 20765237. The next prime is 20765287. The reversal of 20765251 is 15256702.

It is a cyclic number.

It is not a de Polignac number, because 20765251 - 2⁷ = 20765123 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20765201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10125 + ... + 12001.

It is an arithmetic number, because the mean of its divisors is an integer number (1498644).

Almost surely, 2^20765251 is an apocalyptic number.

20765251 is a deficient number, since it is larger than the sum of its proper divisors (3213053).

20765251 is a wasteful number, since it uses less digits than its factorization.

20765251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1950.

The product of its (nonzero) digits is 4200, while the sum is 28.

The square root of 20765251 is about 4556.8904968191. The cubic root of 20765251 is about 274.8605397561.

The spelling of 20765251 in words is "twenty million, seven hundred sixty-five thousand, two hundred fifty-one".