21716722 has 4 divisors (see below), whose sum is σ = 32575086. Its totient is φ = 10858360.

The previous prime is 21716713. The next prime is 21716729. The reversal of 21716722 is 22761712.

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

It can be written as a sum of positive squares in only one way, i.e., 16329681 + 5387041 = 4041^2 + 2321^2 .

It is not an unprimeable number, because it can be changed into a prime (21716729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5429179 + ... + 5429182.

Almost surely, 2^21716722 is an apocalyptic number.

21716722 is a deficient number, since it is larger than the sum of its proper divisors (10858364).

21716722 is a wasteful number, since it uses less digits than its factorization.

21716722 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10858363.

The product of its digits is 2352, while the sum is 28.

The square root of 21716722 is about 4660.1203847111. The cubic root of 21716722 is about 278.9960731367.

The spelling of 21716722 in words is "twenty-one million, seven hundred sixteen thousand, seven hundred twenty-two".