1491612738 has 144 divisors (see below), whose sum is σ = 3892324800. Its totient is φ = 373000320.

The previous prime is 1491612701. The next prime is 1491612739. The reversal of 1491612738 is 8372161941.

It is a happy number.

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

It is a self number, because there is not a number n which added to its sum of digits gives 1491612738.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1491612739) 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, 4273788 + ... + 4274136.

Almost surely, 2^1491612738 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1491612738, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1946162400).

1491612738 is an abundant number, since it is smaller than the sum of its proper divisors (2400712062).

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

1491612738 is a wasteful number, since it uses less digits than its factorization.

1491612738 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 441 (or 401 counting only the distinct ones).

The product of its digits is 72576, while the sum is 42.

The square root of 1491612738 is about 38621.4025897559. The cubic root of 1491612738 is about 1142.5766939340.

The spelling of 1491612738 in words is "one billion, four hundred ninety-one million, six hundred twelve thousand, seven hundred thirty-eight".