20769391 has 4 divisors (see below), whose sum is σ = 21672432. Its totient is φ = 19866352.

The previous prime is 20769389. The next prime is 20769401. The reversal of 20769391 is 19396702.

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

It is a cyclic number.

It is not a de Polignac number, because 20769391 - 2¹ = 20769389 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20769391.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20769311) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 451486 + ... + 451531.

It is an arithmetic number, because the mean of its divisors is an integer number (5418108).

Almost surely, 2^20769391 is an apocalyptic number.

20769391 is a deficient number, since it is larger than the sum of its proper divisors (903041).

20769391 is an equidigital number, since it uses as much as digits as its factorization.

20769391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 903040.

The product of its (nonzero) digits is 20412, while the sum is 37.

The square root of 20769391 is about 4557.3447313101. The cubic root of 20769391 is about 274.8788049983.

The spelling of 20769391 in words is "twenty million, seven hundred sixty-nine thousand, three hundred ninety-one".