21864966 has 16 divisors (see below), whose sum is σ = 43914288. Its totient is φ = 7257600.

The previous prime is 21864959. The next prime is 21864989. The reversal of 21864966 is 66946812.

It is a super-3 number, since 3×21864966³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6115 + ... + 9006.

It is an arithmetic number, because the mean of its divisors is an integer number (2744643).

Almost surely, 2^21864966 is an apocalyptic number.

21864966 is an abundant number, since it is smaller than the sum of its proper divisors (22049322).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21864966 is a wasteful number, since it uses less digits than its factorization.

21864966 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15367.

The product of its digits is 124416, while the sum is 42.

The square root of 21864966 is about 4675.9989307099. The cubic root of 21864966 is about 279.6294673620.

The spelling of 21864966 in words is "twenty-one million, eight hundred sixty-four thousand, nine hundred sixty-six".