1491123816 has 192 divisors, whose sum is σ = 5155113600. Its totient is φ = 393216768.

The previous prime is 1491123797. The next prime is 1491123847. The reversal of 1491123816 is 6183211941.

It is a Harshad number since it is a multiple of its sum of digits (36).

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

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 172690 + ... + 181118.

It is an arithmetic number, because the mean of its divisors is an integer number (26849550).

Almost surely, 2^1491123816 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 1491123816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2577556800).

1491123816 is an abundant number, since it is smaller than the sum of its proper divisors (3663989784).

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

1491123816 is a wasteful number, since it uses less digits than its factorization.

1491123816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8470 (or 8454 counting only the distinct ones).

The product of its digits is 10368, while the sum is 36.

The square root of 1491123816 is about 38615.0723940795. The cubic root of 1491123816 is about 1142.4518420616.

The spelling of 1491123816 in words is "one billion, four hundred ninety-one million, one hundred twenty-three thousand, eight hundred sixteen".