21299135 has 16 divisors (see below), whose sum is σ = 30028320. Its totient is φ = 14298240.

The previous prime is 21299129. The next prime is 21299141. The reversal of 21299135 is 53199212.

21299135 = T₂₃₄ + T₂₃₅ + ... + T₅₁₉.

It is an interprime number because it is at equal distance from previous prime (21299129) and next prime (21299141).

It is not a de Polignac number, because 21299135 - 2⁴ = 21299119 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14180 + ... + 15609.

It is an arithmetic number, because the mean of its divisors is an integer number (1876770).

Almost surely, 2^21299135 is an apocalyptic number.

21299135 is a deficient number, since it is larger than the sum of its proper divisors (8729185).

21299135 is a wasteful number, since it uses less digits than its factorization.

21299135 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29818.

The product of its digits is 4860, while the sum is 32.

The square root of 21299135 is about 4615.0985904962. The cubic root of 21299135 is about 277.1962317299.

The spelling of 21299135 in words is "twenty-one million, two hundred ninety-nine thousand, one hundred thirty-five".