21995284 has 12 divisors (see below), whose sum is σ = 38564064. Its totient is φ = 10976984.

The previous prime is 21995243. The next prime is 21995287. The reversal of 21995284 is 48259912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21995287) 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, 2632 + ... + 7135.

It is an arithmetic number, because the mean of its divisors is an integer number (3213672).

Almost surely, 2^21995284 is an apocalyptic number.

It is an amenable number.

21995284 is a deficient number, since it is larger than the sum of its proper divisors (16568780).

21995284 is a wasteful number, since it uses less digits than its factorization.

21995284 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10334 (or 10332 counting only the distinct ones).

The product of its digits is 51840, while the sum is 40.

The square root of 21995284 is about 4689.9130055898. The cubic root of 21995284 is about 280.1839097900.

The spelling of 21995284 in words is "twenty-one million, nine hundred ninety-five thousand, two hundred eighty-four".