21537134 has 4 divisors (see below), whose sum is σ = 32305704. Its totient is φ = 10768566.

The previous prime is 21537121. The next prime is 21537137. The reversal of 21537134 is 43173512.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21537137) by changing a digit.

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, 5384282 + ... + 5384285.

It is an arithmetic number, because the mean of its divisors is an integer number (8076426).

Almost surely, 2^21537134 is an apocalyptic number.

21537134 is a deficient number, since it is larger than the sum of its proper divisors (10768570).

21537134 is a wasteful number, since it uses less digits than its factorization.

21537134 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10768569.

The product of its digits is 2520, while the sum is 26.

The square root of 21537134 is about 4640.8117824363. The cubic root of 21537134 is about 278.2248840247.

The spelling of 21537134 in words is "twenty-one million, five hundred thirty-seven thousand, one hundred thirty-four".