21492803 has 4 divisors (see below), whose sum is σ = 21637200. Its totient is φ = 21348408.

The previous prime is 21492791. The next prime is 21492817. The reversal of 21492803 is 30829412.

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 21492803 - 2⁸ = 21492547 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21492853) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 71975 + ... + 72272.

It is an arithmetic number, because the mean of its divisors is an integer number (5409300).

Almost surely, 2^21492803 is an apocalyptic number.

21492803 is a deficient number, since it is larger than the sum of its proper divisors (144397).

21492803 is a wasteful number, since it uses less digits than its factorization.

21492803 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144396.

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 21492803 is about 4636.0331103218. The cubic root of 21492803 is about 278.0338579952.

The spelling of 21492803 in words is "twenty-one million, four hundred ninety-two thousand, eight hundred three".