21503134 has 4 divisors (see below), whose sum is σ = 32254704. Its totient is φ = 10751566.

The previous prime is 21503129. The next prime is 21503149. The reversal of 21503134 is 43130512.

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

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 as a sum of consecutive naturals, namely, 5375782 + ... + 5375785.

It is an arithmetic number, because the mean of its divisors is an integer number (8063676).

Almost surely, 2^21503134 is an apocalyptic number.

21503134 is a deficient number, since it is larger than the sum of its proper divisors (10751570).

21503134 is a wasteful number, since it uses less digits than its factorization.

21503134 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10751569.

The product of its (nonzero) digits is 360, while the sum is 19.

The square root of 21503134 is about 4637.1471833445. The cubic root of 21503134 is about 278.0783986054.

Adding to 21503134 its reverse (43130512), we get a palindrome (64633646).

The spelling of 21503134 in words is "twenty-one million, five hundred three thousand, one hundred thirty-four".