20726545565 has 24 divisors (see below), whose sum is σ = 28527133824. Its totient is φ = 14418456800.

The previous prime is 20726545547. The next prime is 20726545573. The reversal of 20726545565 is 56554562702.

It is not a de Polignac number, because 20726545565 - 2¹² = 20726541469 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 730841 + ... + 758670.

It is an arithmetic number, because the mean of its divisors is an integer number (1188630576).

Almost surely, 2^20726545565 is an apocalyptic number.

It is an amenable number.

20726545565 is a deficient number, since it is larger than the sum of its proper divisors (7800588259).

20726545565 is a wasteful number, since it uses less digits than its factorization.

20726545565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1489561 (or 1489550 counting only the distinct ones).

The product of its (nonzero) digits is 2520000, while the sum is 47.

The spelling of 20726545565 in words is "twenty billion, seven hundred twenty-six million, five hundred forty-five thousand, five hundred sixty-five".