21066072 has 32 divisors (see below), whose sum is σ = 53214000. Its totient is φ = 6948864.

The previous prime is 21066049. The next prime is 21066107. The reversal of 21066072 is 27066012.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2197 + ... + 6852.

Almost surely, 2^21066072 is an apocalyptic number.

It is an amenable number.

21066072 is an abundant number, since it is smaller than the sum of its proper divisors (32147928).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21066072 is a wasteful number, since it uses less digits than its factorization.

21066072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9155 (or 9151 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 24.

The square root of 21066072 is about 4589.7790796508. The cubic root of 21066072 is about 276.1814601704.

The spelling of 21066072 in words is "twenty-one million, sixty-six thousand, seventy-two".