20390765 has 16 divisors (see below), whose sum is σ = 25664256. Its totient is φ = 15523200.

The previous prime is 20390759. The next prime is 20390767. The reversal of 20390765 is 56709302.

It is not a de Polignac number, because 20390765 - 2¹⁰ = 20389741 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 (20390767) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32000 + ... + 32630.

It is an arithmetic number, because the mean of its divisors is an integer number (1604016).

Almost surely, 2^20390765 is an apocalyptic number.

It is an amenable number.

20390765 is a deficient number, since it is larger than the sum of its proper divisors (5273491).

20390765 is a wasteful number, since it uses less digits than its factorization.

20390765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 940.

The product of its (nonzero) digits is 11340, while the sum is 32.

The square root of 20390765 is about 4515.6134688434. The cubic root of 20390765 is about 273.1982039115.

The spelling of 20390765 in words is "twenty million, three hundred ninety thousand, seven hundred sixty-five".