165817672020 has 384 divisors, whose sum is σ = 692648570880. Its totient is φ = 31805084160.

The previous prime is 165817671973. The next prime is 165817672039. The reversal of 165817672020 is 20276718561.

165817672020 is a `hidden beast` number, since 1 + 6 + 581 + 7 + 67 + 2 + 0 + 2 + 0 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 387159 + ... + 693921.

It is an arithmetic number, because the mean of its divisors is an integer number (1803772320).

Almost surely, 2^165817672020 is an apocalyptic number.

165817672020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 165817672020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (346324285440).

165817672020 is an abundant number, since it is smaller than the sum of its proper divisors (526830898860).

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

165817672020 is a wasteful number, since it uses less digits than its factorization.

165817672020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 306812 (or 306804 counting only the distinct ones).

The product of its (nonzero) digits is 282240, while the sum is 45.

The spelling of 165817672020 in words is "one hundred sixty-five billion, eight hundred seventeen million, six hundred seventy-two thousand, twenty".