20778226658 has 18 divisors (see below), whose sum is σ = 36258375393. Its totient is φ = 8904342720.

The previous prime is 20778226649. The next prime is 20778226661. The reversal of 20778226658 is 85662287702.

It can be written as a sum of positive squares in 2 ways, for example, as 16808344609 + 3969882049 = 129647^2 + 63007^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=101927.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1419698 + ... + 1434258.

Almost surely, 2^20778226658 is an apocalyptic number.

20778226658 is a deficient number, since it is larger than the sum of its proper divisors (15480148735).

20778226658 is an frugal number, since it uses more digits than its factorization.

20778226658 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29138 (or 14570 counting only the distinct ones).

The product of its (nonzero) digits is 4515840, while the sum is 53.

The spelling of 20778226658 in words is "twenty billion, seven hundred seventy-eight million, two hundred twenty-six thousand, six hundred fifty-eight".