491922823 has 18 divisors (see below), whose sum is σ = 574742552. Its totient is φ = 412443600.

The previous prime is 491922811. The next prime is 491922841. The reversal of 491922823 is 328229194.

It is not a de Polignac number, because 491922823 - 2²¹ = 489825671 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 (491922803) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 4870473 + ... + 4870573.

Almost surely, 2^491922823 is an apocalyptic number.

491922823 is a deficient number, since it is larger than the sum of its proper divisors (82819729).

491922823 is an frugal number, since it uses more digits than its factorization.

491922823 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 375 (or 191 counting only the distinct ones).

The product of its digits is 62208, while the sum is 40.

The square root of 491922823 is about 22179.3332406545. Note that the first 3 decimals coincide. The cubic root of 491922823 is about 789.4033967020.

The spelling of 491922823 in words is "four hundred ninety-one million, nine hundred twenty-two thousand, eight hundred twenty-three".