21374418 has 32 divisors (see below), whose sum is σ = 46569600. Its totient is φ = 6500736.

The previous prime is 21374399. The next prime is 21374443. The reversal of 21374418 is 81447312.

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 in 15 ways as a sum of consecutive naturals, for example, 5403 + ... + 8481.

It is an arithmetic number, because the mean of its divisors is an integer number (1455300).

Almost surely, 2^21374418 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21374418, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23284800).

21374418 is an abundant number, since it is smaller than the sum of its proper divisors (25195182).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21374418 is a wasteful number, since it uses less digits than its factorization.

21374418 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3186.

The product of its digits is 5376, while the sum is 30.

The square root of 21374418 is about 4623.2475598869. The cubic root of 21374418 is about 277.5224362997.

It can be divided in two parts, 2137 and 4418, that added together give a triangular number (6555 = T₁₁₄).

The spelling of 21374418 in words is "twenty-one million, three hundred seventy-four thousand, four hundred eighteen".