20917151712 has 144 divisors (see below), whose sum is σ = 61540773840. Its totient is φ = 6734592000.

The previous prime is 20917151711. The next prime is 20917151719. The reversal of 20917151712 is 21715171902.

It is a tau number, because it is divible by the number of its divisors (144).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20917151711) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1183839 + ... + 1201377.

It is an arithmetic number, because the mean of its divisors is an integer number (427366485).

Almost surely, 2^20917151712 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20917151712, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30770386920).

20917151712 is an abundant number, since it is smaller than the sum of its proper divisors (40623622128).

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

20917151712 is a wasteful number, since it uses less digits than its factorization.

20917151712 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17697 (or 17686 counting only the distinct ones).

The product of its (nonzero) digits is 8820, while the sum is 36.

The spelling of 20917151712 in words is "twenty billion, nine hundred seventeen million, one hundred fifty-one thousand, seven hundred twelve".