21913166 has 16 divisors (see below), whose sum is σ = 36015408. Its totient is φ = 9916800.

The previous prime is 21913159. The next prime is 21913169. The reversal of 21913166 is 66131912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21913169) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3236 + ... + 7368.

It is an arithmetic number, because the mean of its divisors is an integer number (2250963).

Almost surely, 2^21913166 is an apocalyptic number.

21913166 is a deficient number, since it is larger than the sum of its proper divisors (14102242).

21913166 is a wasteful number, since it uses less digits than its factorization.

21913166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4387.

The product of its digits is 1944, while the sum is 29.

The square root of 21913166 is about 4681.1500723647. The cubic root of 21913166 is about 279.8347919975.

The spelling of 21913166 in words is "twenty-one million, nine hundred thirteen thousand, one hundred sixty-six".