491565399 has 48 divisors (see below), whose sum is σ = 746640000. Its totient is φ = 287134848.

The previous prime is 491565391. The next prime is 491565409. The reversal of 491565399 is 993565194.

It is not a de Polignac number, because 491565399 - 2³ = 491565391 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491565391) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 984852 + ... + 985350.

It is an arithmetic number, because the mean of its divisors is an integer number (15555000).

Almost surely, 2^491565399 is an apocalyptic number.

491565399 is a deficient number, since it is larger than the sum of its proper divisors (255074601).

491565399 is a wasteful number, since it uses less digits than its factorization.

491565399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 624 (or 611 counting only the distinct ones).

The product of its digits is 1312200, while the sum is 51.

The square root of 491565399 is about 22171.2741853056. The cubic root of 491565399 is about 789.2121606857.

The spelling of 491565399 in words is "four hundred ninety-one million, five hundred sixty-five thousand, three hundred ninety-nine".