20491403 has 6 divisors (see below), whose sum is σ = 21174732. Its totient is φ = 19829460.

The previous prime is 20491399. The next prime is 20491421. The reversal of 20491403 is 30419402.

It is not a de Polignac number, because 20491403 - 2² = 20491399 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20491433) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 9701 + ... + 11622.

It is an arithmetic number, because the mean of its divisors is an integer number (3529122).

Almost surely, 2^20491403 is an apocalyptic number.

20491403 is a deficient number, since it is larger than the sum of its proper divisors (683329).

20491403 is an equidigital number, since it uses as much as digits as its factorization.

20491403 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21385 (or 21354 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 20491403 is about 4526.7430896838. The cubic root of 20491403 is about 273.6469203171.

The spelling of 20491403 in words is "twenty million, four hundred ninety-one thousand, four hundred three".