20782779 has 8 divisors (see below), whose sum is σ = 27732240. Its totient is φ = 13844256.

The previous prime is 20782771. The next prime is 20782781. The reversal of 20782779 is 97728702.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20782779 - 2³ = 20782771 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20782779.

It is not an unprimeable number, because it can be changed into a prime (20782771) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4257 + ... + 7725.

It is an arithmetic number, because the mean of its divisors is an integer number (3466530).

Almost surely, 2^20782779 is an apocalyptic number.

20782779 is a deficient number, since it is larger than the sum of its proper divisors (6949461).

20782779 is a wasteful number, since it uses less digits than its factorization.

20782779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5469.

The product of its (nonzero) digits is 98784, while the sum is 42.

The square root of 20782779 is about 4558.8133324364. The cubic root of 20782779 is about 274.9378548279.

The spelling of 20782779 in words is "twenty million, seven hundred eighty-two thousand, seven hundred seventy-nine".