491989489 has 4 divisors (see below), whose sum is σ = 492285940. Its totient is φ = 491693040.

The previous prime is 491989453. The next prime is 491989493. The reversal of 491989489 is 984989194.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 171400464 + 320589025 = 13092^2 + 17905^2 .

It is a cyclic number.

It is not a de Polignac number, because 491989489 - 2⁹ = 491988977 is a prime.

It is a super-2 number, since 2×491989489² = 484107314572962242, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (491989429) 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, 145722 + ... + 149059.

It is an arithmetic number, because the mean of its divisors is an integer number (123071485).

Almost surely, 2^491989489 is an apocalyptic number.

It is an amenable number.

491989489 is a deficient number, since it is larger than the sum of its proper divisors (296451).

491989489 is a wasteful number, since it uses less digits than its factorization.

491989489 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 296450.

The product of its digits is 6718464, while the sum is 61.

The square root of 491989489 is about 22180.8360753151. The cubic root of 491989489 is about 789.4390554051.

The spelling of 491989489 in words is "four hundred ninety-one million, nine hundred eighty-nine thousand, four hundred eighty-nine".