491009623 has 16 divisors (see below), whose sum is σ = 569388960. Its totient is φ = 419337216.

The previous prime is 491009587. The next prime is 491009639. The reversal of 491009623 is 326900194.

It is a cyclic number.

It is not a de Polignac number, because 491009623 - 2⁹ = 491009111 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491009653) 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, 5790 + ... + 31867.

It is an arithmetic number, because the mean of its divisors is an integer number (35586810).

Almost surely, 2^491009623 is an apocalyptic number.

491009623 is a deficient number, since it is larger than the sum of its proper divisors (78379337).

491009623 is a wasteful number, since it uses less digits than its factorization.

491009623 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37746.

The product of its (nonzero) digits is 11664, while the sum is 34.

The square root of 491009623 is about 22158.7369450517. The cubic root of 491009623 is about 788.9146142558.

The spelling of 491009623 in words is "four hundred ninety-one million, nine thousand, six hundred twenty-three".