20783399 has 32 divisors (see below), whose sum is σ = 26880000. Its totient is φ = 15960672.

The previous prime is 20783393. The next prime is 20783407. The reversal of 20783399 is 99338702.

It is not a de Polignac number, because 20783399 - 2⁴ = 20783383 is a prime.

It is a hoax number, since the sum of its digits (41) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20783393) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 263042 + ... + 263120.

It is an arithmetic number, because the mean of its divisors is an integer number (840000).

Almost surely, 2^20783399 is an apocalyptic number.

20783399 is a deficient number, since it is larger than the sum of its proper divisors (6096601).

20783399 is an equidigital number, since it uses as much as digits as its factorization.

20783399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172 (or 158 counting only the distinct ones).

The product of its (nonzero) digits is 81648, while the sum is 41.

The square root of 20783399 is about 4558.8813320814. The cubic root of 20783399 is about 274.9405888186.

The spelling of 20783399 in words is "twenty million, seven hundred eighty-three thousand, three hundred ninety-nine".