21634318 has 4 divisors (see below), whose sum is σ = 32451480. Its totient is φ = 10817158.

The previous prime is 21634309. The next prime is 21634337. The reversal of 21634318 is 81343612.

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

It is a congruent number.

It is an unprimeable number.

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, 5408578 + ... + 5408581.

It is an arithmetic number, because the mean of its divisors is an integer number (8112870).

Almost surely, 2^21634318 is an apocalyptic number.

21634318 is a deficient number, since it is larger than the sum of its proper divisors (10817162).

21634318 is a wasteful number, since it uses less digits than its factorization.

21634318 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10817161.

The product of its digits is 3456, while the sum is 28.

The square root of 21634318 is about 4651.2705790999. The cubic root of 21634318 is about 278.6427427577.

It can be divided in two parts, 21634 and 318, that added together give a cube (21952 = 28³).

The spelling of 21634318 in words is "twenty-one million, six hundred thirty-four thousand, three hundred eighteen".