21238766 has 8 divisors (see below), whose sum is σ = 32294784. Its totient is φ = 10473840.

The previous prime is 21238757. The next prime is 21238843. The reversal of 21238766 is 66783212.

It is a happy number.

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, 72590 + ... + 72881.

It is an arithmetic number, because the mean of its divisors is an integer number (4036848).

Almost surely, 2^21238766 is an apocalyptic number.

21238766 is a deficient number, since it is larger than the sum of its proper divisors (11056018).

21238766 is a wasteful number, since it uses less digits than its factorization.

21238766 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 145546.

The product of its digits is 24192, while the sum is 35.

The square root of 21238766 is about 4608.5535691798. The cubic root of 21238766 is about 276.9340944137.

The spelling of 21238766 in words is "twenty-one million, two hundred thirty-eight thousand, seven hundred sixty-six".