20259779 has 6 divisors (see below), whose sum is σ = 20554260. Its totient is φ = 19969460.

The previous prime is 20259769. The next prime is 20259793. The reversal of 20259779 is 97795202.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-20259779 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20259739) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3032 + ... + 7050.

It is an arithmetic number, because the mean of its divisors is an integer number (3425710).

Almost surely, 2^20259779 is an apocalyptic number.

20259779 is a deficient number, since it is larger than the sum of its proper divisors (294481).

20259779 is an frugal number, since it uses more digits than its factorization.

20259779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4161 (or 4090 counting only the distinct ones).

The product of its (nonzero) digits is 79380, while the sum is 41.

The square root of 20259779 is about 4501.0864244091. The cubic root of 20259779 is about 272.6119574746.

The spelling of 20259779 in words is "twenty million, two hundred fifty-nine thousand, seven hundred seventy-nine".