2115615720 has 64 divisors (see below), whose sum is σ = 6364656000. Its totient is φ = 562581248.

The previous prime is 2115615713. The next prime is 2115615721. The reversal of 2115615720 is 275165112.

It is a super-2 number, since 2×2115615720² = 8951659749422236800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (2115615721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18526 + ... + 67634.

It is an arithmetic number, because the mean of its divisors is an integer number (99447750).

Almost surely, 2^2115615720 is an apocalyptic number.

2115615720 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 2115615720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3182328000).

2115615720 is an abundant number, since it is smaller than the sum of its proper divisors (4249040280).

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

2115615720 is a wasteful number, since it uses less digits than its factorization.

2115615720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49482 (or 49478 counting only the distinct ones).

The product of its (nonzero) digits is 4200, while the sum is 30.

The square root of 2115615720 is about 45995.8228538201. The cubic root of 2115615720 is about 1283.7454828838.

The spelling of 2115615720 in words is "two billion, one hundred fifteen million, six hundred fifteen thousand, seven hundred twenty".