20865407760 has 80 divisors (see below), whose sum is σ = 71869745280. Its totient is φ = 5564108160.

The previous prime is 20865407747. The next prime is 20865407807. The reversal of 20865407760 is 6770456802.

20865407760 is a `hidden beast` number, since 20 + 86 + 540 + 7 + 7 + 6 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (45).

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, 4827796 + ... + 4832115.

It is an arithmetic number, because the mean of its divisors is an integer number (898371816).

Almost surely, 2^20865407760 is an apocalyptic number.

20865407760 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20865407760 is an abundant number, since it is smaller than the sum of its proper divisors (51004337520).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20865407760 is a wasteful number, since it uses less digits than its factorization.

20865407760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9659933 (or 9659921 counting only the distinct ones).

The product of its (nonzero) digits is 564480, while the sum is 45.

The spelling of 20865407760 in words is "twenty billion, eight hundred sixty-five million, four hundred seven thousand, seven hundred sixty".