21768867 has 12 divisors (see below), whose sum is σ = 31519800. Its totient is φ = 14477568.

The previous prime is 21768853. The next prime is 21768883. The reversal of 21768867 is 76886712.

It is not a de Polignac number, because 21768867 - 2⁷ = 21768739 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21768847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1348 + ... + 6734.

It is an arithmetic number, because the mean of its divisors is an integer number (2626650).

Almost surely, 2^21768867 is an apocalyptic number.

21768867 is a deficient number, since it is larger than the sum of its proper divisors (9750933).

21768867 is a wasteful number, since it uses less digits than its factorization.

21768867 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5842 (or 5839 counting only the distinct ones).

The product of its digits is 225792, while the sum is 45.

The square root of 21768867 is about 4665.7118427953. The cubic root of 21768867 is about 279.2191979955.

The spelling of 21768867 in words is "twenty-one million, seven hundred sixty-eight thousand, eight hundred sixty-seven".