21347424 has 72 divisors (see below), whose sum is σ = 69385680. Its totient is φ = 6098688.

The previous prime is 21347423. The next prime is 21347441. The reversal of 21347424 is 42474312.

It is a tau number, because it is divible by the number of its divisors (72).

It is a super-2 number, since 2×21347424² = 911425022871552, which contains 22 as substring.

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 (21347423) 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 11 ways as a sum of consecutive naturals, for example, 3279 + ... + 7310.

It is an arithmetic number, because the mean of its divisors is an integer number (963690).

Almost surely, 2^21347424 is an apocalyptic number.

21347424 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21347424 is an abundant number, since it is smaller than the sum of its proper divisors (48038256).

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

21347424 is a wasteful number, since it uses less digits than its factorization.

21347424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10612 (or 10601 counting only the distinct ones).

The product of its digits is 5376, while the sum is 27.

The square root of 21347424 is about 4620.3272611364. The cubic root of 21347424 is about 277.4055583176.

The spelling of 21347424 in words is "twenty-one million, three hundred forty-seven thousand, four hundred twenty-four".