20189765 has 4 divisors (see below), whose sum is σ = 24227724. Its totient is φ = 16151808.

The previous prime is 20189759. The next prime is 20189777. The reversal of 20189765 is 56798102.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4831204 + 15358561 = 2198^2 + 3919^2 .

It is a cyclic number.

It is not a de Polignac number, because 20189765 - 2¹⁶ = 20124229 is a prime.

It is a super-2 number, since 2×20189765² = 815253221510450, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

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, 2018972 + ... + 2018981.

It is an arithmetic number, because the mean of its divisors is an integer number (6056931).

Almost surely, 2^20189765 is an apocalyptic number.

It is an amenable number.

20189765 is a deficient number, since it is larger than the sum of its proper divisors (4037959).

20189765 is an equidigital number, since it uses as much as digits as its factorization.

20189765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4037958.

The product of its (nonzero) digits is 30240, while the sum is 38.

The square root of 20189765 is about 4493.3022377757. The cubic root of 20189765 is about 272.2975630854.

The spelling of 20189765 in words is "twenty million, one hundred eighty-nine thousand, seven hundred sixty-five".