491787879 has 16 divisors (see below), whose sum is σ = 716304384. Its totient is φ = 297646400.

The previous prime is 491787869. The next prime is 491787889. The reversal of 491787879 is 978787194.

It is an interprime number because it is at equal distance from previous prime (491787869) and next prime (491787889).

It is a cyclic number.

It is not a de Polignac number, because 491787879 - 2⁵ = 491787847 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491787869) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15322 + ... + 34904.

It is an arithmetic number, because the mean of its divisors is an integer number (44769024).

Almost surely, 2^491787879 is an apocalyptic number.

491787879 is a deficient number, since it is larger than the sum of its proper divisors (224516505).

491787879 is a wasteful number, since it uses less digits than its factorization.

491787879 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20358.

The product of its digits is 7112448, while the sum is 60.

The square root of 491787879 is about 22176.2909207108. The cubic root of 491787879 is about 789.3312071978.

The spelling of 491787879 in words is "four hundred ninety-one million, seven hundred eighty-seven thousand, eight hundred seventy-nine".