1491438816 has 144 divisors (see below), whose sum is σ = 4929724800. Its totient is φ = 418869504.

The previous prime is 1491438811. The next prime is 1491438833. The reversal of 1491438816 is 6188341941.

It is a tau number, because it is divible by the number of its divisors (144).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1491438811) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 112675 + ... + 125213.

It is an arithmetic number, because the mean of its divisors is an integer number (34234200).

Almost surely, 2^1491438816 is an apocalyptic number.

1491438816 is a gapful number since it is divisible by the number (16) 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 1491438816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2464862400).

1491438816 is an abundant number, since it is smaller than the sum of its proper divisors (3438285984).

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

1491438816 is a wasteful number, since it uses less digits than its factorization.

1491438816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12621 (or 12610 counting only the distinct ones).

The product of its digits is 165888, while the sum is 45.

The square root of 1491438816 is about 38619.1508969320. The cubic root of 1491438816 is about 1142.5322840719.

The spelling of 1491438816 in words is "one billion, four hundred ninety-one million, four hundred thirty-eight thousand, eight hundred sixteen".