21669072 has 20 divisors (see below), whose sum is σ = 55978560. Its totient is φ = 7223008.

The previous prime is 21669071. The next prime is 21669077. The reversal of 21669072 is 27096612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21669071) 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, 225672 + ... + 225767.

It is an arithmetic number, because the mean of its divisors is an integer number (2798928).

Almost surely, 2^21669072 is an apocalyptic number.

It is an amenable number.

21669072 is an abundant number, since it is smaller than the sum of its proper divisors (34309488).

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

21669072 is a wasteful number, since it uses less digits than its factorization.

21669072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 451450 (or 451444 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 33.

The square root of 21669072 is about 4655.0050483324. The cubic root of 21669072 is about 278.7918695444.

The spelling of 21669072 in words is "twenty-one million, six hundred sixty-nine thousand, seventy-two".