21499345 has 8 divisors (see below), whose sum is σ = 29484864. Its totient is φ = 14742384.

The previous prime is 21499343. The next prime is 21499349. The reversal of 21499345 is 54399412.

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

It is a cyclic number.

It is not a de Polignac number, because 21499345 - 2¹ = 21499343 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21499343) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 307099 + ... + 307168.

It is an arithmetic number, because the mean of its divisors is an integer number (3685608).

Almost surely, 2^21499345 is an apocalyptic number.

It is an amenable number.

21499345 is a deficient number, since it is larger than the sum of its proper divisors (7985519).

21499345 is an equidigital number, since it uses as much as digits as its factorization.

21499345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 614279.

The product of its digits is 38880, while the sum is 37.

The square root of 21499345 is about 4636.7386167435. The cubic root of 21499345 is about 278.0620645377.

The spelling of 21499345 in words is "twenty-one million, four hundred ninety-nine thousand, three hundred forty-five".