21651134 has 4 divisors (see below), whose sum is σ = 32476704. Its totient is φ = 10825566.

The previous prime is 21651121. The next prime is 21651163. The reversal of 21651134 is 43115612.

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

It is a plaindrome in base 11.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5412782 + ... + 5412785.

It is an arithmetic number, because the mean of its divisors is an integer number (8119176).

Almost surely, 2^21651134 is an apocalyptic number.

21651134 is a deficient number, since it is larger than the sum of its proper divisors (10825570).

21651134 is a wasteful number, since it uses less digits than its factorization.

21651134 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10825569.

The product of its digits is 720, while the sum is 23.

The square root of 21651134 is about 4653.0779060746. The cubic root of 21651134 is about 278.7149188694.

Adding to 21651134 its reverse (43115612), we get a palindrome (64766746).

The spelling of 21651134 in words is "twenty-one million, six hundred fifty-one thousand, one hundred thirty-four".