1491491904 has 224 divisors, whose sum is σ = 4697821440. Its totient is φ = 408748032.

The previous prime is 1491491873. The next prime is 1491491909. The reversal of 1491491904 is 4091941941.

It is a tau number, because it is divible by the number of its divisors (224).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is not an unprimeable number, because it can be changed into a prime (1491491909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4425624 + ... + 4425960.

Almost surely, 2^1491491904 is an apocalyptic number.

1491491904 is a gapful number since it is divisible by the number (14) 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 1491491904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2348910720).

1491491904 is an abundant number, since it is smaller than the sum of its proper divisors (3206329536).

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

1491491904 is a wasteful number, since it uses less digits than its factorization.

1491491904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 485 (or 475 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 42.

The square root of 1491491904 is about 38619.8382182008. The cubic root of 1491491904 is about 1142.5458401167.

The spelling of 1491491904 in words is "one billion, four hundred ninety-one million, four hundred ninety-one thousand, nine hundred four".