21299667 has 8 divisors (see below), whose sum is σ = 28481424. Its totient is φ = 14158848.

The previous prime is 21299647. The next prime is 21299669. The reversal of 21299667 is 76699212.

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

It is a de Polignac number, because none of the positive numbers 2^k-21299667 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21299669) 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, 8998 + ... + 11115.

It is an arithmetic number, because the mean of its divisors is an integer number (3560178).

Almost surely, 2^21299667 is an apocalyptic number.

21299667 is a deficient number, since it is larger than the sum of its proper divisors (7181757).

21299667 is a wasteful number, since it uses less digits than its factorization.

21299667 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20469.

The product of its digits is 81648, while the sum is 42.

The square root of 21299667 is about 4615.1562270415. The cubic root of 21299667 is about 277.1985396040.

The spelling of 21299667 in words is "twenty-one million, two hundred ninety-nine thousand, six hundred sixty-seven".