21886668 has 36 divisors (see below), whose sum is σ = 56373408. Its totient is φ = 7157280.

The previous prime is 21886663. The next prime is 21886679. The reversal of 21886668 is 86668812.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×21886668² = 958052472284448, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21886663) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3828 + ... + 7643.

It is an arithmetic number, because the mean of its divisors is an integer number (1565928).

Almost surely, 2^21886668 is an apocalyptic number.

It is an amenable number.

21886668 is an abundant number, since it is smaller than the sum of its proper divisors (34486740).

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

21886668 is a wasteful number, since it uses less digits than its factorization.

21886668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11534 (or 11529 counting only the distinct ones).

The product of its digits is 221184, while the sum is 45.

The square root of 21886668 is about 4678.3189288461. The cubic root of 21886668 is about 279.7219518727.

The spelling of 21886668 in words is "twenty-one million, eight hundred eighty-six thousand, six hundred sixty-eight".