1491913728 has 110 divisors (see below), whose sum is σ = 4455393756. Its totient is φ = 497276928.

The previous prime is 1491913711. The next prime is 1491913751. The reversal of 1491913728 is 8273191941.

1491913728 is a `hidden beast` number, since 1 + 491 + 9 + 137 + 28 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 73951 + ... + 91937.

Almost surely, 2^1491913728 is an apocalyptic number.

1491913728 is a gapful number since it is divisible by the number (18) 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 1491913728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2227696878).

1491913728 is an abundant number, since it is smaller than the sum of its proper divisors (2963480028).

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

1491913728 is an equidigital number, since it uses as much as digits as its factorization.

1491913728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18019 (or 17992 counting only the distinct ones).

The product of its digits is 108864, while the sum is 45.

The square root of 1491913728 is about 38625.2990668034. The cubic root of 1491913728 is about 1142.6535416351.

The spelling of 1491913728 in words is "one billion, four hundred ninety-one million, nine hundred thirteen thousand, seven hundred twenty-eight".