21998265 has 8 divisors (see below), whose sum is σ = 35197248. Its totient is φ = 11732400.

The previous prime is 21998243. The next prime is 21998267. The reversal of 21998265 is 56289912.

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

It is not a de Polignac number, because 21998265 - 2⁶ = 21998201 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21998267) 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, 733261 + ... + 733290.

It is an arithmetic number, because the mean of its divisors is an integer number (4399656).

Almost surely, 2^21998265 is an apocalyptic number.

It is an amenable number.

21998265 is a deficient number, since it is larger than the sum of its proper divisors (13198983).

21998265 is a wasteful number, since it uses less digits than its factorization.

21998265 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1466559.

The product of its digits is 77760, while the sum is 42.

The square root of 21998265 is about 4690.2308045554. The cubic root of 21998265 is about 280.1965669049.

The spelling of 21998265 in words is "twenty-one million, nine hundred ninety-eight thousand, two hundred sixty-five".