21439794 has 16 divisors (see below), whose sum is σ = 43138368. Its totient is φ = 7103472.

The previous prime is 21439793. The next prime is 21439801. The reversal of 21439794 is 49793412.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21439793) 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 7 ways as a sum of consecutive naturals, for example, 9697 + ... + 11700.

It is an arithmetic number, because the mean of its divisors is an integer number (2696148).

Almost surely, 2^21439794 is an apocalyptic number.

21439794 is an abundant number, since it is smaller than the sum of its proper divisors (21698574).

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

21439794 is a wasteful number, since it uses less digits than its factorization.

21439794 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21569.

The product of its digits is 54432, while the sum is 39.

The square root of 21439794 is about 4630.3125164507. The cubic root of 21439794 is about 277.8050925791.

The spelling of 21439794 in words is "twenty-one million, four hundred thirty-nine thousand, seven hundred ninety-four".