21819672 has 64 divisors (see below), whose sum is σ = 69273600. Its totient is φ = 6233760.

The previous prime is 21819659. The next prime is 21819673. The reversal of 21819672 is 27691812.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21819673) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5704 + ... + 8727.

It is an arithmetic number, because the mean of its divisors is an integer number (1082400).

Almost surely, 2^21819672 is an apocalyptic number.

It is an amenable number.

21819672 is an abundant number, since it is smaller than the sum of its proper divisors (47453928).

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

21819672 is a wasteful number, since it uses less digits than its factorization.

21819672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14453 (or 14443 counting only the distinct ones).

The product of its digits is 12096, while the sum is 36.

The square root of 21819672 is about 4671.1531766792. The cubic root of 21819672 is about 279.4362466505.

The spelling of 21819672 in words is "twenty-one million, eight hundred nineteen thousand, six hundred seventy-two".