20872745 has 4 divisors (see below), whose sum is σ = 25047300. Its totient is φ = 16698192.

The previous prime is 20872727. The next prime is 20872763. The reversal of 20872745 is 54727802.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54727802 = 2 ⋅27363901.

It is an interprime number because it is at equal distance from previous prime (20872727) and next prime (20872763).

It can be written as a sum of positive squares in 2 ways, for example, as 12503296 + 8369449 = 3536^2 + 2893^2 .

It is a cyclic number.

It is not a de Polignac number, because 20872745 - 2⁶ = 20872681 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2087270 + ... + 2087279.

It is an arithmetic number, because the mean of its divisors is an integer number (6261825).

Almost surely, 2^20872745 is an apocalyptic number.

It is an amenable number.

20872745 is a deficient number, since it is larger than the sum of its proper divisors (4174555).

20872745 is an equidigital number, since it uses as much as digits as its factorization.

20872745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4174554.

The product of its (nonzero) digits is 31360, while the sum is 35.

The square root of 20872745 is about 4568.6699377390. The cubic root of 20872745 is about 275.3340073828.

The spelling of 20872745 in words is "twenty million, eight hundred seventy-two thousand, seven hundred forty-five".