2157281280 has 768 divisors, whose sum is σ = 9814521600. Its totient is φ = 424673280.

The previous prime is 2157281257. The next prime is 2157281363. The reversal of 2157281280 is 821827512.

2157281280 is a `hidden beast` number, since 2 + 1 + 572 + 8 + 1 + 2 + 80 = 666.

It is a tau number, because it is divible by the number of its divisors (768).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 113541111 + ... + 113541129.

It is an arithmetic number, because the mean of its divisors is an integer number (12779325).

Almost surely, 2^2157281280 is an apocalyptic number.

2157281280 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 2157281280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4907260800).

2157281280 is an abundant number, since it is smaller than the sum of its proper divisors (7657240320).

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

2157281280 is a wasteful number, since it uses less digits than its factorization.

2157281280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78 (or 47 counting only the distinct ones).

The product of its (nonzero) digits is 17920, while the sum is 36.

The square root of 2157281280 is about 46446.5421748487. The cubic root of 2157281280 is about 1292.1182432909.

The spelling of 2157281280 in words is "two billion, one hundred fifty-seven million, two hundred eighty-one thousand, two hundred eighty".