20171088720 has 160 divisors (see below), whose sum is σ = 71356266240. Its totient is φ = 5233559040.

The previous prime is 20171088703. The next prime is 20171088733. The reversal of 20171088720 is 2788017102.

It is a happy number.

It is a super-2 number, since 2×20171088720² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 46276 + ... + 206115.

It is an arithmetic number, because the mean of its divisors is an integer number (445976664).

Almost surely, 2^20171088720 is an apocalyptic number.

20171088720 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 20171088720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35678133120).

20171088720 is an abundant number, since it is smaller than the sum of its proper divisors (51185177520).

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

20171088720 is a wasteful number, since it uses less digits than its factorization.

20171088720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 252450 (or 252438 counting only the distinct ones).

The product of its (nonzero) digits is 12544, while the sum is 36.

The spelling of 20171088720 in words is "twenty billion, one hundred seventy-one million, eighty-eight thousand, seven hundred twenty".