20780279 has 8 divisors (see below), whose sum is σ = 22415232. Its totient is φ = 19150560.

The previous prime is 20780257. The next prime is 20780303. The reversal of 20780279 is 97208702.

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

It is not a de Polignac number, because 20780279 - 2²⁰ = 19731703 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 (20780219) 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, 12077 + ... + 13689.

It is an arithmetic number, because the mean of its divisors is an integer number (2801904).

Almost surely, 2^20780279 is an apocalyptic number.

20780279 is a deficient number, since it is larger than the sum of its proper divisors (1634953).

20780279 is a wasteful number, since it uses less digits than its factorization.

20780279 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2617.

The product of its (nonzero) digits is 14112, while the sum is 35.

The square root of 20780279 is about 4558.5391300284. The cubic root of 20780279 is about 274.9268301200.

The spelling of 20780279 in words is "twenty million, seven hundred eighty thousand, two hundred seventy-nine".