1491138889 has 4 divisors (see below), whose sum is σ = 1494599040. Its totient is φ = 1487678740.

The previous prime is 1491138863. The next prime is 1491138911. The reversal of 1491138889 is 9888311941.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1491138889 - 2¹¹ = 1491136841 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1491138589) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1729429 + ... + 1730290.

It is an arithmetic number, because the mean of its divisors is an integer number (373649760).

Almost surely, 2^1491138889 is an apocalyptic number.

It is an amenable number.

1491138889 is a deficient number, since it is larger than the sum of its proper divisors (3460151).

1491138889 is an equidigital number, since it uses as much as digits as its factorization.

1491138889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3460150.

The product of its digits is 497664, while the sum is 52.

The square root of 1491138889 is about 38615.2675634910. The cubic root of 1491138889 is about 1142.4556915337.

The spelling of 1491138889 in words is "one billion, four hundred ninety-one million, one hundred thirty-eight thousand, eight hundred eighty-nine".