21179424 has 48 divisors (see below), whose sum is σ = 63540288. Its totient is φ = 6051072.

The previous prime is 21179423. The next prime is 21179449. The reversal of 21179424 is 42497112.

It is a tau number, because it is divible by the number of its divisors (48).

It is a junction number, because it is equal to n+sod(n) for n = 21179391 and 21179400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21179423) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15087 + ... + 16430.

It is an arithmetic number, because the mean of its divisors is an integer number (1323756).

Almost surely, 2^21179424 is an apocalyptic number.

21179424 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21179424 is an abundant number, since it is smaller than the sum of its proper divisors (42360864).

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

21179424 is a wasteful number, since it uses less digits than its factorization.

21179424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31537 (or 31529 counting only the distinct ones).

The product of its digits is 4032, while the sum is 30.

The square root of 21179424 is about 4602.1108200477. The cubic root of 21179424 is about 276.6759320134.

The spelling of 21179424 in words is "twenty-one million, one hundred seventy-nine thousand, four hundred twenty-four".