21166654 has 8 divisors (see below), whose sum is σ = 31775400. Its totient is φ = 10574856.

The previous prime is 21166643. The next prime is 21166679. The reversal of 21166654 is 45666112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 429 + ... + 6520.

It is an arithmetic number, because the mean of its divisors is an integer number (3971925).

Almost surely, 2^21166654 is an apocalyptic number.

21166654 is a deficient number, since it is larger than the sum of its proper divisors (10608746).

21166654 is a wasteful number, since it uses less digits than its factorization.

21166654 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8474.

The product of its digits is 8640, while the sum is 31.

The square root of 21166654 is about 4600.7232040191. The cubic root of 21166654 is about 276.6203141649.

The spelling of 21166654 in words is "twenty-one million, one hundred sixty-six thousand, six hundred fifty-four".