21869424 has 30 divisors (see below), whose sum is σ = 61204416. Its totient is φ = 7289760.

The previous prime is 21869423. The next prime is 21869461. The reversal of 21869424 is 42496812.

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 (21869423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 75792 + ... + 76079.

Almost surely, 2^21869424 is an apocalyptic number.

21869424 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21869424 is an abundant number, since it is smaller than the sum of its proper divisors (39334992).

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

21869424 is a wasteful number, since it uses less digits than its factorization.

21869424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 151885 (or 151876 counting only the distinct ones).

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

The square root of 21869424 is about 4676.4755960018. The cubic root of 21869424 is about 279.6484704170.

The spelling of 21869424 in words is "twenty-one million, eight hundred sixty-nine thousand, four hundred twenty-four".