21766242 has 8 divisors (see below), whose sum is σ = 43532496. Its totient is φ = 7255412.

The previous prime is 21766237. The next prime is 21766243. The reversal of 21766242 is 24266712.

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

21766242 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (21766243) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1813848 + ... + 1813859.

It is an arithmetic number, because the mean of its divisors is an integer number (5441562).

Almost surely, 2^21766242 is an apocalyptic number.

21766242 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21766242 is a wasteful number, since it uses less digits than its factorization.

21766242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3627712.

The product of its digits is 8064, while the sum is 30.

The square root of 21766242 is about 4665.4305267574. The cubic root of 21766242 is about 279.2079743236.

The spelling of 21766242 in words is "twenty-one million, seven hundred sixty-six thousand, two hundred forty-two".