21512134 has 8 divisors (see below), whose sum is σ = 36877968. Its totient is φ = 9219480.

The previous prime is 21512129. The next prime is 21512137. The reversal of 21512134 is 43121512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21512137) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 768277 + ... + 768304.

It is an arithmetic number, because the mean of its divisors is an integer number (4609746).

Almost surely, 2^21512134 is an apocalyptic number.

21512134 is a deficient number, since it is larger than the sum of its proper divisors (15365834).

21512134 is a wasteful number, since it uses less digits than its factorization.

21512134 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1536590.

The product of its digits is 240, while the sum is 19.

The square root of 21512134 is about 4638.1175060578. The cubic root of 21512134 is about 278.1171891759.

Adding to 21512134 its reverse (43121512), we get a palindrome (64633646).

The spelling of 21512134 in words is "twenty-one million, five hundred twelve thousand, one hundred thirty-four".