21018814 has 16 divisors (see below), whose sum is σ = 32550336. Its totient is φ = 10172800.

The previous prime is 21018799. The next prime is 21018821. The reversal of 21018814 is 41881012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10299 + ... + 12169.

It is an arithmetic number, because the mean of its divisors is an integer number (2034396).

Almost surely, 2^21018814 is an apocalyptic number.

21018814 is a deficient number, since it is larger than the sum of its proper divisors (11531522).

21018814 is a wasteful number, since it uses less digits than its factorization.

21018814 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2051.

The product of its (nonzero) digits is 512, while the sum is 25.

The square root of 21018814 is about 4584.6280110823. The cubic root of 21018814 is about 275.9747841557.

Adding to 21018814 its reverse (41881012), we get a palindrome (62899826).

The spelling of 21018814 in words is "twenty-one million, eighteen thousand, eight hundred fourteen".