21942766 has 4 divisors (see below), whose sum is σ = 32914152. Its totient is φ = 10971382.

The previous prime is 21942757. The next prime is 21942769. The reversal of 21942766 is 66724912.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21942769) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5485690 + ... + 5485693.

It is an arithmetic number, because the mean of its divisors is an integer number (8228538).

Almost surely, 2^21942766 is an apocalyptic number.

21942766 is a deficient number, since it is larger than the sum of its proper divisors (10971386).

21942766 is a wasteful number, since it uses less digits than its factorization.

21942766 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10971385.

The product of its digits is 36288, while the sum is 37.

The square root of 21942766 is about 4684.3106216390. The cubic root of 21942766 is about 279.9607342898.

The spelling of 21942766 in words is "twenty-one million, nine hundred forty-two thousand, seven hundred sixty-six".