21352499 has 8 divisors (see below), whose sum is σ = 24506880. Its totient is φ = 18224136.

The previous prime is 21352483. The next prime is 21352517. The reversal of 21352499 is 99425312.

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

It is not a de Polignac number, because 21352499 - 2⁴ = 21352483 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21352099) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4709 + ... + 8054.

It is an arithmetic number, because the mean of its divisors is an integer number (3063360).

Almost surely, 2^21352499 is an apocalyptic number.

21352499 is a deficient number, since it is larger than the sum of its proper divisors (3154381).

21352499 is a wasteful number, since it uses less digits than its factorization.

21352499 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13009.

The product of its digits is 19440, while the sum is 35.

The square root of 21352499 is about 4620.8764320202. The cubic root of 21352499 is about 277.4275394500.

The spelling of 21352499 in words is "twenty-one million, three hundred fifty-two thousand, four hundred ninety-nine".