21111299 has 16 divisors (see below), whose sum is σ = 24554880. Its totient is φ = 17948160.

The previous prime is 21111287. The next prime is 21111301. The reversal of 21111299 is 99211112.

It is not a de Polignac number, because 21111299 - 2⁴ = 21111283 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21111239) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16739 + ... + 17955.

It is an arithmetic number, because the mean of its divisors is an integer number (1534680).

Almost surely, 2^21111299 is an apocalyptic number.

21111299 is a deficient number, since it is larger than the sum of its proper divisors (3443581).

21111299 is a wasteful number, since it uses less digits than its factorization.

21111299 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1330.

The product of its digits is 324, while the sum is 26.

The square root of 21111299 is about 4594.7033636569. The cubic root of 21111299 is about 276.3789646477.

The spelling of 21111299 in words is "twenty-one million, one hundred eleven thousand, two hundred ninety-nine".