21298911 has 8 divisors (see below), whose sum is σ = 28431024. Its totient is φ = 14183040.

The previous prime is 21298903. The next prime is 21298931. The reversal of 21298911 is 11989212.

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

It is not a de Polignac number, because 21298911 - 2³ = 21298903 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21298931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 570 + ... + 6551.

It is an arithmetic number, because the mean of its divisors is an integer number (3553878).

Almost surely, 2^21298911 is an apocalyptic number.

21298911 is a deficient number, since it is larger than the sum of its proper divisors (7132113).

21298911 is an equidigital number, since it uses as much as digits as its factorization.

21298911 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8121.

The product of its digits is 2592, while the sum is 33.

The square root of 21298911 is about 4615.0743222618. The cubic root of 21298911 is about 277.1952599820.

The spelling of 21298911 in words is "twenty-one million, two hundred ninety-eight thousand, nine hundred eleven".