21954668 has 6 divisors (see below), whose sum is σ = 38420676. Its totient is φ = 10977332.

The previous prime is 21954643. The next prime is 21954679. The reversal of 21954668 is 86645912.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2744330 + ... + 2744337.

It is an arithmetic number, because the mean of its divisors is an integer number (6403446).

Almost surely, 2^21954668 is an apocalyptic number.

It is an amenable number.

21954668 is a deficient number, since it is larger than the sum of its proper divisors (16466008).

21954668 is a wasteful number, since it uses less digits than its factorization.

21954668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5488671 (or 5488669 counting only the distinct ones).

The product of its digits is 103680, while the sum is 41.

The square root of 21954668 is about 4685.5808604697. The cubic root of 21954668 is about 280.0113430779.

It can be divided in two parts, 21954 and 668, that added together give a palindrome (22622).

The spelling of 21954668 in words is "twenty-one million, nine hundred fifty-four thousand, six hundred sixty-eight".