20779779 has 8 divisors (see below), whose sum is σ = 27846400. Its totient is φ = 13783176.

The previous prime is 20779769. The next prime is 20779789. The reversal of 20779779 is 97797702.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20779769) and next prime (20779789).

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

It is not a de Polignac number, because 20779779 - 2¹³ = 20771587 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20779739) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16807 + ... + 18000.

It is an arithmetic number, because the mean of its divisors is an integer number (3480800).

Almost surely, 2^20779779 is an apocalyptic number.

20779779 is a deficient number, since it is larger than the sum of its proper divisors (7066621).

20779779 is a wasteful number, since it uses less digits than its factorization.

20779779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35009.

The product of its (nonzero) digits is 388962, while the sum is 48.

The square root of 20779779 is about 4558.4842875675. The cubic root of 20779779 is about 274.9246250724.

The spelling of 20779779 in words is "twenty million, seven hundred seventy-nine thousand, seven hundred seventy-nine".