21027722 has 4 divisors (see below), whose sum is σ = 31541586. Its totient is φ = 10513860.

The previous prime is 21027709. The next prime is 21027767. The reversal of 21027722 is 22772012.

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., 15358561 + 5669161 = 3919^2 + 2381^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5256929 + ... + 5256932.

Almost surely, 2^21027722 is an apocalyptic number.

21027722 is a deficient number, since it is larger than the sum of its proper divisors (10513864).

21027722 is a wasteful number, since it uses less digits than its factorization.

21027722 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10513863.

The product of its (nonzero) digits is 784, while the sum is 23.

The square root of 21027722 is about 4585.5994155617. The cubic root of 21027722 is about 276.0137656790.

Adding to 21027722 its reverse (22772012), we get a palindrome (43799734).

The spelling of 21027722 in words is "twenty-one million, twenty-seven thousand, seven hundred twenty-two".