21867424 has 12 divisors (see below), whose sum is σ = 43051554. Its totient is φ = 10933696.

The previous prime is 21867403. The next prime is 21867427. The reversal of 21867424 is 42476812.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 19963024 + 1904400 = 4468^2 + 1380^2 .

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 21867424.

It is not an unprimeable number, because it can be changed into a prime (21867427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 341647 + ... + 341710.

Almost surely, 2^21867424 is an apocalyptic number.

It is an amenable number.

21867424 is a deficient number, since it is larger than the sum of its proper divisors (21184130).

21867424 is an equidigital number, since it uses as much as digits as its factorization.

21867424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 683367 (or 683359 counting only the distinct ones).

The product of its digits is 21504, while the sum is 34.

The square root of 21867424 is about 4676.2617548636. The cubic root of 21867424 is about 279.6399453641.

The spelling of 21867424 in words is "twenty-one million, eight hundred sixty-seven thousand, four hundred twenty-four".