20783745 has 12 divisors (see below), whose sum is σ = 36025236. Its totient is φ = 11084640.

The previous prime is 20783723. The next prime is 20783767. The reversal of 20783745 is 54738702.

It is an interprime number because it is at equal distance from previous prime (20783723) and next prime (20783767).

It can be written as a sum of positive squares in 2 ways, for example, as 4210704 + 16573041 = 2052^2 + 4071^2 .

It is not a de Polignac number, because 20783745 - 2⁵ = 20783713 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 230886 + ... + 230975.

It is an arithmetic number, because the mean of its divisors is an integer number (3002103).

Almost surely, 2^20783745 is an apocalyptic number.

It is an amenable number.

20783745 is a deficient number, since it is larger than the sum of its proper divisors (15241491).

20783745 is a wasteful number, since it uses less digits than its factorization.

20783745 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 461872 (or 461869 counting only the distinct ones).

The product of its (nonzero) digits is 47040, while the sum is 36.

The square root of 20783745 is about 4558.9192798294. The cubic root of 20783745 is about 274.9421145382.

It can be divided in two parts, 20783 and 745, that added together give a triangular number (21528 = T₂₀₇).

The spelling of 20783745 in words is "twenty million, seven hundred eighty-three thousand, seven hundred forty-five".