21348424 has 8 divisors (see below), whose sum is σ = 40028310. Its totient is φ = 10674208.

The previous prime is 21348421. The next prime is 21348433. The reversal of 21348424 is 42484312.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 21325924 + 22500 = 4618^2 + 150^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a junction number, because it is equal to n+sod(n) for n = 21348392 and 21348401.

It is not an unprimeable number, because it can be changed into a prime (21348421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1334269 + ... + 1334284.

Almost surely, 2^21348424 is an apocalyptic number.

It is an amenable number.

21348424 is a deficient number, since it is larger than the sum of its proper divisors (18679886).

21348424 is a wasteful number, since it uses less digits than its factorization.

21348424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2668559 (or 2668555 counting only the distinct ones).

The product of its digits is 6144, while the sum is 28.

The square root of 21348424 is about 4620.4354773116. The cubic root of 21348424 is about 277.4098898508.

The spelling of 21348424 in words is "twenty-one million, three hundred forty-eight thousand, four hundred twenty-four".