20003491 has 4 divisors (see below), whose sum is σ = 20873232. Its totient is φ = 19133752.

The previous prime is 20003461. The next prime is 20003497. The reversal of 20003491 is 19430002.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20003491 - 2⁹ = 20002979 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20003497) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 434836 + ... + 434881.

It is an arithmetic number, because the mean of its divisors is an integer number (5218308).

Almost surely, 2^20003491 is an apocalyptic number.

20003491 is a deficient number, since it is larger than the sum of its proper divisors (869741).

20003491 is an equidigital number, since it uses as much as digits as its factorization.

20003491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 869740.

The product of its (nonzero) digits is 216, while the sum is 19.

The square root of 20003491 is about 4472.5262436346. The cubic root of 20003491 is about 271.4575541272.

Adding to 20003491 its reverse (19430002), we get a palindrome (39433493).

The spelling of 20003491 in words is "twenty million, three thousand, four hundred ninety-one".