21667006 has 4 divisors (see below), whose sum is σ = 32500512. Its totient is φ = 10833502.

The previous prime is 21667003. The next prime is 21667021. The reversal of 21667006 is 60076612.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21667001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5416750 + ... + 5416753.

It is an arithmetic number, because the mean of its divisors is an integer number (8125128).

Almost surely, 2^21667006 is an apocalyptic number.

21667006 is a deficient number, since it is larger than the sum of its proper divisors (10833506).

21667006 is a wasteful number, since it uses less digits than its factorization.

21667006 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10833505.

The product of its (nonzero) digits is 3024, while the sum is 28.

The square root of 21667006 is about 4654.7831313607. The cubic root of 21667006 is about 278.7830089540.

The spelling of 21667006 in words is "twenty-one million, six hundred sixty-seven thousand, six".