21451814 has 8 divisors (see below), whose sum is σ = 33215808. Its totient is φ = 10379880.

The previous prime is 21451813. The next prime is 21451819. The reversal of 21451814 is 41815412.

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

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21451811) 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 in 3 ways as a sum of consecutive naturals, for example, 172937 + ... + 173060.

It is an arithmetic number, because the mean of its divisors is an integer number (4151976).

Almost surely, 2^21451814 is an apocalyptic number.

21451814 is a deficient number, since it is larger than the sum of its proper divisors (11763994).

21451814 is a wasteful number, since it uses less digits than its factorization.

21451814 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 346030.

The product of its digits is 1280, while the sum is 26.

The square root of 21451814 is about 4631.6103031235. The cubic root of 21451814 is about 277.8569990694.

The spelling of 21451814 in words is "twenty-one million, four hundred fifty-one thousand, eight hundred fourteen".