2115691720 has 64 divisors (see below), whose sum is σ = 4940144640. Its totient is φ = 814598400.

The previous prime is 2115691693. The next prime is 2115691727. The reversal of 2115691720 is 271965112.

It is not an unprimeable number, because it can be changed into a prime (2115691727) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 232374 + ... + 241306.

It is an arithmetic number, because the mean of its divisors is an integer number (77189760).

Almost surely, 2^2115691720 is an apocalyptic number.

2115691720 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 2115691720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2470072320).

2115691720 is an abundant number, since it is smaller than the sum of its proper divisors (2824452920).

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

2115691720 is a wasteful number, since it uses less digits than its factorization.

2115691720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9166 (or 9162 counting only the distinct ones).

The product of its (nonzero) digits is 7560, while the sum is 34.

The square root of 2115691720 is about 45996.6490083789. The cubic root of 2115691720 is about 1283.7608548450.

The spelling of 2115691720 in words is "two billion, one hundred fifteen million, six hundred ninety-one thousand, seven hundred twenty".