21765572 has 12 divisors (see below), whose sum is σ = 38735760. Its totient is φ = 10698216.

The previous prime is 21765571. The next prime is 21765599. The reversal of 21765572 is 27556712.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21765571) 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 3 ways as a sum of consecutive naturals, for example, 45878 + ... + 46349.

It is an arithmetic number, because the mean of its divisors is an integer number (3227980).

Almost surely, 2^21765572 is an apocalyptic number.

It is an amenable number.

21765572 is a deficient number, since it is larger than the sum of its proper divisors (16970188).

21765572 is a wasteful number, since it uses less digits than its factorization.

21765572 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92290 (or 92288 counting only the distinct ones).

The product of its digits is 29400, while the sum is 35.

The square root of 21765572 is about 4665.3587214704. The cubic root of 21765572 is about 279.2051094705.

The spelling of 21765572 in words is "twenty-one million, seven hundred sixty-five thousand, five hundred seventy-two".