21288014 has 20 divisors (see below), whose sum is σ = 35173320. Its totient is φ = 9663060.

The previous prime is 21288013. The next prime is 21288023. The reversal of 21288014 is 41088212.

It is a Smith number, since the sum of its digits (26) coincides with the sum of the digits of its prime factors.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21288013) 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 9 ways as a sum of consecutive naturals, for example, 28919 + ... + 29645.

It is an arithmetic number, because the mean of its divisors is an integer number (1758666).

Almost surely, 2^21288014 is an apocalyptic number.

21288014 is a deficient number, since it is larger than the sum of its proper divisors (13885306).

21288014 is an frugal number, since it uses more digits than its factorization.

21288014 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 773 (or 740 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 26.

The square root of 21288014 is about 4613.8935835149. The cubic root of 21288014 is about 277.1479788161.

The spelling of 21288014 in words is "twenty-one million, two hundred eighty-eight thousand, fourteen".