2157149728 has 72 divisors (see below), whose sum is σ = 4474952244. Its totient is φ = 1022976000.

The previous prime is 2157149723. The next prime is 2157149749. The reversal of 2157149728 is 8279417512.

It can be written as a sum of positive squares in 6 ways, for example, as 660078864 + 1497070864 = 25692^2 + 38692^2 .

It is not an unprimeable number, because it can be changed into a prime (2157149723) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1795528 + ... + 1796728.

Almost surely, 2^2157149728 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 2157149728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2237476122).

2157149728 is an abundant number, since it is smaller than the sum of its proper divisors (2317802516).

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

2157149728 is a wasteful number, since it uses less digits than its factorization.

2157149728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1326 (or 1281 counting only the distinct ones).

The product of its digits is 282240, while the sum is 46.

The square root of 2157149728 is about 46445.1259875565. The cubic root of 2157149728 is about 1292.0919781030.

The spelling of 2157149728 in words is "two billion, one hundred fifty-seven million, one hundred forty-nine thousand, seven hundred twenty-eight".