21441764 has 12 divisors (see below), whose sum is σ = 37559424. Its totient is φ = 10710504.

The previous prime is 21441751. The next prime is 21441769. The reversal of 21441764 is 46714412.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21441769) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3809 + ... + 7575.

It is an arithmetic number, because the mean of its divisors is an integer number (3129952).

Almost surely, 2^21441764 is an apocalyptic number.

It is an amenable number.

21441764 is a deficient number, since it is larger than the sum of its proper divisors (16117660).

21441764 is a wasteful number, since it uses less digits than its factorization.

21441764 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5194 (or 5192 counting only the distinct ones).

The product of its digits is 5376, while the sum is 29.

The square root of 21441764 is about 4630.5252401860. The cubic root of 21441764 is about 277.8136010451.

The spelling of 21441764 in words is "twenty-one million, four hundred forty-one thousand, seven hundred sixty-four".