2115521280 has 288 divisors, whose sum is σ = 7695414720. Its totient is φ = 550010880.

The previous prime is 2115521273. The next prime is 2115521299. The reversal of 2115521280 is 821255112.

It is a happy number.

2115521280 is a `hidden beast` number, since 2 + 115 + 521 + 28 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a super-2 number, since 2×2115521280² = 8950860572265676800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1416214 + ... + 1417706.

It is an arithmetic number, because the mean of its divisors is an integer number (26720190).

Almost surely, 2^2115521280 is an apocalyptic number.

2115521280 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 2115521280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3847707360).

2115521280 is an abundant number, since it is smaller than the sum of its proper divisors (5579893440).

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

2115521280 is a wasteful number, since it uses less digits than its factorization.

2115521280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1564 (or 1544 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 27.

The square root of 2115521280 is about 45994.7962273995. The cubic root of 2115521280 is about 1283.7263806864.

Adding to 2115521280 its reverse (821255112), we get a palindrome (2936776392).

The spelling of 2115521280 in words is "two billion, one hundred fifteen million, five hundred twenty-one thousand, two hundred eighty".