20165618780 has 12 divisors (see below), whose sum is σ = 42347799480. Its totient is φ = 8066247504.

The previous prime is 20165618777. The next prime is 20165618813. The reversal of 20165618780 is 8781656102.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 504140450 + ... + 504140489.

It is an arithmetic number, because the mean of its divisors is an integer number (3528983290).

Almost surely, 2^20165618780 is an apocalyptic number.

20165618780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20165618780 is an abundant number, since it is smaller than the sum of its proper divisors (22182180700).

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

20165618780 is a wasteful number, since it uses less digits than its factorization.

20165618780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1008280948 (or 1008280946 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 44.

The spelling of 20165618780 in words is "twenty billion, one hundred sixty-five million, six hundred eighteen thousand, seven hundred eighty".