21803398 has 16 divisors (see below), whose sum is σ = 33261840. Its totient is φ = 10717696.

The previous prime is 21803387. The next prime is 21803407. The reversal of 21803398 is 89330812.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 61590 + ... + 61942.

It is an arithmetic number, because the mean of its divisors is an integer number (2078865).

Almost surely, 2^21803398 is an apocalyptic number.

21803398 is a deficient number, since it is larger than the sum of its proper divisors (11458442).

21803398 is a wasteful number, since it uses less digits than its factorization.

21803398 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 791.

The product of its (nonzero) digits is 10368, while the sum is 34.

The square root of 21803398 is about 4669.4108836126. The cubic root of 21803398 is about 279.3667577274.

It can be divided in two parts, 21803 and 398, that added together give a square (22201 = 149²).

The spelling of 21803398 in words is "twenty-one million, eight hundred three thousand, three hundred ninety-eight".