20172164987520 has 3072 divisors, whose sum is σ = 95558561280000. Its totient is φ = 4029465968640.

The previous prime is 20172164987489. The next prime is 20172164987561. The reversal of 20172164987520 is 2578946127102.

20172164987520 is a `hidden beast` number, since 2 + 0 + 1 + 7 + 21 + 6 + 4 + 98 + 7 + 520 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 13175809155 + ... + 13175810685.

It is an arithmetic number, because the mean of its divisors is an integer number (31106302500).

Almost surely, 2^{20172164987520} is an apocalyptic number.

20172164987520 is a gapful number since it is divisible by the number (20) 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 20172164987520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47779280640000).

20172164987520 is an abundant number, since it is smaller than the sum of its proper divisors (75386396292480).

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

20172164987520 is a wasteful number, since it uses less digits than its factorization.

20172164987520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1618 (or 1580 counting only the distinct ones).

The product of its (nonzero) digits is 3386880, while the sum is 54.

The spelling of 20172164987520 in words is "twenty trillion, one hundred seventy-two billion, one hundred sixty-four million, nine hundred eighty-seven thousand, five hundred twenty".