2158786728 has 288 divisors, whose sum is σ = 7148100960. Its totient is φ = 608549760.

The previous prime is 2158786727. The next prime is 2158786771. The reversal of 2158786728 is 8276878512.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (2158786723) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 12478450 + ... + 12478622.

It is an arithmetic number, because the mean of its divisors is an integer number (24819795).

Almost surely, 2^2158786728 is an apocalyptic number.

2158786728 is a gapful number since it is divisible by the number (28) 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 2158786728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3574050480).

2158786728 is an abundant number, since it is smaller than the sum of its proper divisors (4989314232).

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

2158786728 is a wasteful number, since it uses less digits than its factorization.

2158786728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 339 (or 316 counting only the distinct ones).

The product of its digits is 3010560, while the sum is 54.

The square root of 2158786728 is about 46462.7455925713. The cubic root of 2158786728 is about 1292.4187394960.

The spelling of 2158786728 in words is "two billion, one hundred fifty-eight million, seven hundred eighty-six thousand, seven hundred twenty-eight".