21440078 has 16 divisors (see below), whose sum is σ = 35434800. Its totient is φ = 9648000.

The previous prime is 21440059. The next prime is 21440087. The reversal of 21440078 is 87004412.

It is a Curzon number.

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, 2603 + ... + 7046.

It is an arithmetic number, because the mean of its divisors is an integer number (2214675).

Almost surely, 2^21440078 is an apocalyptic number.

21440078 is a deficient number, since it is larger than the sum of its proper divisors (13994722).

21440078 is a wasteful number, since it uses less digits than its factorization.

21440078 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9763.

The product of its (nonzero) digits is 1792, while the sum is 26.

The square root of 21440078 is about 4630.3431838256. The cubic root of 21440078 is about 277.8063192125.

The spelling of 21440078 in words is "twenty-one million, four hundred forty thousand, seventy-eight".