2181015756 has 72 divisors (see below), whose sum is σ = 5770162944. Its totient is φ = 693300960.

The previous prime is 2181015737. The next prime is 2181015829. The reversal of 2181015756 is 6575101812.

2181015756 is a `hidden beast` number, since 2 + 1 + 81 + 0 + 1 + 575 + 6 = 666.

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

It is a self number, because there is not a number n which added to its sum of digits gives 2181015756.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 283521 + ... + 291111.

It is an arithmetic number, because the mean of its divisors is an integer number (80141152).

Almost surely, 2^2181015756 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 2181015756, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2885081472).

2181015756 is an abundant number, since it is smaller than the sum of its proper divisors (3589147188).

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

2181015756 is a wasteful number, since it uses less digits than its factorization.

2181015756 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7971 (or 7966 counting only the distinct ones).

The product of its (nonzero) digits is 16800, while the sum is 36.

The square root of 2181015756 is about 46701.3464045738. The cubic root of 2181015756 is about 1296.8396122620.

The spelling of 2181015756 in words is "two billion, one hundred eighty-one million, fifteen thousand, seven hundred fifty-six".