21172299 has 16 divisors (see below), whose sum is σ = 28771200. Its totient is φ = 13846976.

The previous prime is 21172273. The next prime is 21172309. The reversal of 21172299 is 99227112.

It is not a de Polignac number, because 21172299 - 2¹¹ = 21170251 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21172499) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 47572 + ... + 48014.

It is an arithmetic number, because the mean of its divisors is an integer number (1798200).

Almost surely, 2^21172299 is an apocalyptic number.

21172299 is a deficient number, since it is larger than the sum of its proper divisors (7598901).

21172299 is a wasteful number, since it uses less digits than its factorization.

21172299 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 714.

The product of its digits is 4536, while the sum is 33.

The square root of 21172299 is about 4601.3366536258. The cubic root of 21172299 is about 276.6449028863.

The spelling of 21172299 in words is "twenty-one million, one hundred seventy-two thousand, two hundred ninety-nine".