20778590449 has 8 divisors (see below), whose sum is σ = 21353402952. Its totient is φ = 20207016960.

The previous prime is 20778590447. The next prime is 20778590453. The reversal of 20778590449 is 94409587702.

It can be written as a sum of positive squares in 4 ways, for example, as 5444226225 + 15334364224 = 73785^2 + 123832^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 20778590449 - 2¹ = 20778590447 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20778590449.

It is not an unprimeable number, because it can be changed into a prime (20778590447) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 796744 + ... + 822409.

It is an arithmetic number, because the mean of its divisors is an integer number (2669175369).

Almost surely, 2^20778590449 is an apocalyptic number.

It is an amenable number.

20778590449 is a deficient number, since it is larger than the sum of its proper divisors (574812503).

20778590449 is a wasteful number, since it uses less digits than its factorization.

20778590449 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1619507.

The product of its (nonzero) digits is 5080320, while the sum is 55.

The spelling of 20778590449 in words is "twenty billion, seven hundred seventy-eight million, five hundred ninety thousand, four hundred forty-nine".