21504046 has 4 divisors (see below), whose sum is σ = 32256072. Its totient is φ = 10752022.

The previous prime is 21504023. The next prime is 21504047. The reversal of 21504046 is 64040512.

It is a semiprime because it is the product of two primes.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21504047) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5376010 + ... + 5376013.

It is an arithmetic number, because the mean of its divisors is an integer number (8064018).

Almost surely, 2^21504046 is an apocalyptic number.

21504046 is a deficient number, since it is larger than the sum of its proper divisors (10752026).

21504046 is a wasteful number, since it uses less digits than its factorization.

21504046 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10752025.

The product of its (nonzero) digits is 960, while the sum is 22.

The square root of 21504046 is about 4637.2455186242. The cubic root of 21504046 is about 278.0823298760.

Adding to 21504046 its reverse (64040512), we get a palindrome (85544558).

The spelling of 21504046 in words is "twenty-one million, five hundred four thousand, forty-six".