20875661 has 16 divisors (see below), whose sum is σ = 22767360. Its totient is φ = 19077120.

The previous prime is 20875637. The next prime is 20875667. The reversal of 20875661 is 16657802.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20875661 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20875667) 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, 86501 + ... + 86741.

It is an arithmetic number, because the mean of its divisors is an integer number (1422960).

Almost surely, 2^20875661 is an apocalyptic number.

It is an amenable number.

20875661 is a deficient number, since it is larger than the sum of its proper divisors (1891699).

20875661 is a wasteful number, since it uses less digits than its factorization.

20875661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 404.

The product of its (nonzero) digits is 20160, while the sum is 35.

The square root of 20875661 is about 4568.9890566733. The cubic root of 20875661 is about 275.3468285136.

The spelling of 20875661 in words is "twenty million, eight hundred seventy-five thousand, six hundred sixty-one".