21722667 has 4 divisors (see below), whose sum is σ = 28963560. Its totient is φ = 14481776.

The previous prime is 21722647. The next prime is 21722671. The reversal of 21722667 is 76622712.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21722667 - 2²² = 17528363 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21722627) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3620442 + ... + 3620447.

It is an arithmetic number, because the mean of its divisors is an integer number (7240890).

Almost surely, 2^21722667 is an apocalyptic number.

21722667 is a deficient number, since it is larger than the sum of its proper divisors (7240893).

21722667 is an equidigital number, since it uses as much as digits as its factorization.

21722667 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7240892.

The product of its digits is 14112, while the sum is 33.

The square root of 21722667 is about 4660.7582001215. The cubic root of 21722667 is about 279.0215294084.

The spelling of 21722667 in words is "twenty-one million, seven hundred twenty-two thousand, six hundred sixty-seven".