20779818 has 8 divisors (see below), whose sum is σ = 41559648. Its totient is φ = 6926604.

The previous prime is 20779799. The next prime is 20779823. The reversal of 20779818 is 81897702.

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

20779818 is an admirable number.

It is a super-2 number, since 2×20779818² = 863601672226248, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20779818.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1731646 + ... + 1731657.

It is an arithmetic number, because the mean of its divisors is an integer number (5194956).

Almost surely, 2^20779818 is an apocalyptic number.

20779818 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20779818 is a wasteful number, since it uses less digits than its factorization.

20779818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3463308.

The product of its (nonzero) digits is 56448, while the sum is 42.

The square root of 20779818 is about 4558.4885653032. The cubic root of 20779818 is about 274.9247970673.

The spelling of 20779818 in words is "twenty million, seven hundred seventy-nine thousand, eight hundred eighteen".