21531134 has 8 divisors (see below), whose sum is σ = 32705760. Its totient is φ = 10629216.

The previous prime is 21531127. The next prime is 21531149. The reversal of 21531134 is 43113512.

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

It is a congruent number.

It is an unprimeable number.

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, 67979 + ... + 68294.

It is an arithmetic number, because the mean of its divisors is an integer number (4088220).

Almost surely, 2^21531134 is an apocalyptic number.

21531134 is a deficient number, since it is larger than the sum of its proper divisors (11174626).

21531134 is a wasteful number, since it uses less digits than its factorization.

21531134 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136354.

The product of its digits is 360, while the sum is 20.

The square root of 21531134 is about 4640.1652987798. The cubic root of 21531134 is about 278.1990448648.

Adding to 21531134 its reverse (43113512), we get a palindrome (64644646).

The spelling of 21531134 in words is "twenty-one million, five hundred thirty-one thousand, one hundred thirty-four".