21522746 has 16 divisors (see below), whose sum is σ = 37055040. Its totient is φ = 9184320.

The previous prime is 21522737. The next prime is 21522749. The reversal of 21522746 is 64722512.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21522749) by changing a digit.

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 in 7 ways as a sum of consecutive naturals, for example, 185 + ... + 6563.

It is an arithmetic number, because the mean of its divisors is an integer number (2315940).

Almost surely, 2^21522746 is an apocalyptic number.

21522746 is a deficient number, since it is larger than the sum of its proper divisors (15532294).

21522746 is a wasteful number, since it uses less digits than its factorization.

21522746 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6629.

The product of its digits is 6720, while the sum is 29.

The square root of 21522746 is about 4639.2613636224. The cubic root of 21522746 is about 278.1629136716.

The spelling of 21522746 in words is "twenty-one million, five hundred twenty-two thousand, seven hundred forty-six".