21677667 has 16 divisors (see below), whose sum is σ = 31699200. Its totient is φ = 13068000.

The previous prime is 21677653. The next prime is 21677681. The reversal of 21677667 is 76677612.

It is an interprime number because it is at equal distance from previous prime (21677653) and next prime (21677681).

It is not a de Polignac number, because 21677667 - 2¹⁰ = 21676643 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21677687) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4917 + ... + 8217.

It is an arithmetic number, because the mean of its divisors is an integer number (1981200).

Almost surely, 2^21677667 is an apocalyptic number.

21677667 is a deficient number, since it is larger than the sum of its proper divisors (10021533).

21677667 is a wasteful number, since it uses less digits than its factorization.

21677667 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3514.

The product of its digits is 148176, while the sum is 42.

The square root of 21677667 is about 4655.9281566622. The cubic root of 21677667 is about 278.8287254431.

Subtracting 21677667 from its reverse (76677612), we obtain a palindrome (54999945).

The spelling of 21677667 in words is "twenty-one million, six hundred seventy-seven thousand, six hundred sixty-seven".