20719678653 has 12 divisors (see below), whose sum is σ = 29993351388. Its totient is φ = 13783152960.

The previous prime is 20719678631. The next prime is 20719678667. The reversal of 20719678653 is 35687691702.

It can be written as a sum of positive squares in 2 ways, for example, as 4320827289 + 16398851364 = 65733^2 + 128058^2 .

It is not a de Polignac number, because 20719678653 - 2²⁰ = 20718630077 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20719678653.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20719678253) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2492800 + ... + 2501097.

It is an arithmetic number, because the mean of its divisors is an integer number (2499445949).

Almost surely, 2^20719678653 is an apocalyptic number.

It is an amenable number.

20719678653 is a deficient number, since it is larger than the sum of its proper divisors (9273672735).

20719678653 is a wasteful number, since it uses less digits than its factorization.

20719678653 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4994364 (or 4994361 counting only the distinct ones).

The product of its (nonzero) digits is 3810240, while the sum is 54.

The spelling of 20719678653 in words is "twenty billion, seven hundred nineteen million, six hundred seventy-eight thousand, six hundred fifty-three".