21528134 has 8 divisors (see below), whose sum is σ = 32312280. Its totient is φ = 10757376.

The previous prime is 21528131. The next prime is 21528139. The reversal of 21528134 is 43182512.

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

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21528131) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3377 + ... + 7379.

It is an arithmetic number, because the mean of its divisors is an integer number (4039035).

Almost surely, 2^21528134 is an apocalyptic number.

21528134 is a deficient number, since it is larger than the sum of its proper divisors (10784146).

21528134 is a wasteful number, since it uses less digits than its factorization.

21528134 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6694.

The product of its digits is 1920, while the sum is 26.

The square root of 21528134 is about 4639.8420231728. The cubic root of 21528134 is about 278.1861234847.

The spelling of 21528134 in words is "twenty-one million, five hundred twenty-eight thousand, one hundred thirty-four".