20000491 has 8 divisors (see below), whose sum is σ = 22885344. Its totient is φ = 17122560.

The previous prime is 20000471. The next prime is 20000503. The reversal of 20000491 is 19400002.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-20000491 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20000471) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8571 + ... + 10651.

It is an arithmetic number, because the mean of its divisors is an integer number (2860668).

Almost surely, 2^20000491 is an apocalyptic number.

20000491 is a deficient number, since it is larger than the sum of its proper divisors (2884853).

20000491 is a wasteful number, since it uses less digits than its factorization.

20000491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3461.

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 20000491 is about 4472.1908501315. The cubic root of 20000491 is about 271.4439829397.

Adding to 20000491 its reverse (19400002), we get a palindrome (39400493).

The spelling of 20000491 in words is "twenty million, four hundred ninety-one", and thus it is an aban number.