21607867 has 4 divisors (see below), whose sum is σ = 22878936. Its totient is φ = 20336800.

The previous prime is 21607853. The next prime is 21607891. The reversal of 21607867 is 76870612.

It is a happy number.

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 21607867 - 2⁷ = 21607739 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21607897) 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, 635509 + ... + 635542.

It is an arithmetic number, because the mean of its divisors is an integer number (5719734).

Almost surely, 2^21607867 is an apocalyptic number.

21607867 is a deficient number, since it is larger than the sum of its proper divisors (1271069).

21607867 is a wasteful number, since it uses less digits than its factorization.

21607867 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1271068.

The product of its (nonzero) digits is 28224, while the sum is 37.

The square root of 21607867 is about 4648.4262928436. The cubic root of 21607867 is about 278.5291364493.

The spelling of 21607867 in words is "twenty-one million, six hundred seven thousand, eight hundred sixty-seven".