20791898565 has 16 divisors (see below), whose sum is σ = 33298776000. Its totient is φ = 11078433152.

The previous prime is 20791898537. The next prime is 20791898623. The reversal of 20791898565 is 56589819702.

It is a cyclic number.

It is not a de Polignac number, because 20791898565 - 2¹⁵ = 20791865797 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20791898499 and 20791898508.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 644955 + ... + 676424.

It is an arithmetic number, because the mean of its divisors is an integer number (2081173500).

Almost surely, 2^20791898565 is an apocalyptic number.

It is an amenable number.

20791898565 is a deficient number, since it is larger than the sum of its proper divisors (12506877435).

20791898565 is a wasteful number, since it uses less digits than its factorization.

20791898565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1322436.

The product of its (nonzero) digits is 10886400, while the sum is 60.

The spelling of 20791898565 in words is "twenty billion, seven hundred ninety-one million, eight hundred ninety-eight thousand, five hundred sixty-five".