8217138720 has 96 divisors (see below), whose sum is σ = 29581711488. Its totient is φ = 1878202368.

The previous prime is 8217138703. The next prime is 8217138749. The reversal of 8217138720 is 278317128.

It is a tau number, because it is divible by the number of its divisors (96).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1219429 + ... + 1226148.

It is an arithmetic number, because the mean of its divisors is an integer number (308142828).

Almost surely, 2^8217138720 is an apocalyptic number.

8217138720 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

8217138720 is an abundant number, since it is smaller than the sum of its proper divisors (21364572768).

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

8217138720 is a wasteful number, since it uses less digits than its factorization.

8217138720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2445602 (or 2445594 counting only the distinct ones).

The product of its (nonzero) digits is 37632, while the sum is 39.

The square root of 8217138720 is about 90648.4347355209. The cubic root of 8217138720 is about 2017.9336055868.

The spelling of 8217138720 in words is "eight billion, two hundred seventeen million, one hundred thirty-eight thousand, seven hundred twenty".