21146424 has 32 divisors (see below), whose sum is σ = 56933520. Its totient is φ = 6506496.

The previous prime is 21146399. The next prime is 21146501. The reversal of 21146424 is 42464112.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (24).

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

It is a junction number, because it is equal to n+sod(n) for n = 21146394 and 21146403.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 33577 + ... + 34200.

Almost surely, 2^21146424 is an apocalyptic number.

21146424 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21146424 is an abundant number, since it is smaller than the sum of its proper divisors (35787096).

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

21146424 is a wasteful number, since it uses less digits than its factorization.

21146424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67799 (or 67795 counting only the distinct ones).

The product of its digits is 1536, while the sum is 24.

The square root of 21146424 is about 4598.5241110600. The cubic root of 21146424 is about 276.5321595814.

The spelling of 21146424 in words is "twenty-one million, one hundred forty-six thousand, four hundred twenty-four".