21928446 has 12 divisors (see below), whose sum is σ = 47511672. Its totient is φ = 7309476.

The previous prime is 21928433. The next prime is 21928447. The reversal of 21928446 is 64482912.

It is a super-3 number, since 3×21928446³ (a number of 23 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21928446.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21928447) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 609106 + ... + 609141.

It is an arithmetic number, because the mean of its divisors is an integer number (3959306).

Almost surely, 2^21928446 is an apocalyptic number.

21928446 is an abundant number, since it is smaller than the sum of its proper divisors (25583226).

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

21928446 is a wasteful number, since it uses less digits than its factorization.

21928446 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1218255 (or 1218252 counting only the distinct ones).

The product of its digits is 27648, while the sum is 36.

The square root of 21928446 is about 4682.7818655154. The cubic root of 21928446 is about 279.8998196032.

The spelling of 21928446 in words is "twenty-one million, nine hundred twenty-eight thousand, four hundred forty-six".