21439078 has 8 divisors (see below), whose sum is σ = 32599368. Its totient is φ = 10572624.

The previous prime is 21438961. The next prime is 21439079. The reversal of 21439078 is 87093412.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21439079) 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, 73276 + ... + 73567.

It is an arithmetic number, because the mean of its divisors is an integer number (4074921).

Almost surely, 2^21439078 is an apocalyptic number.

21439078 is a deficient number, since it is larger than the sum of its proper divisors (11160290).

21439078 is a wasteful number, since it uses less digits than its factorization.

21439078 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146918.

The product of its (nonzero) digits is 12096, while the sum is 34.

The square root of 21439078 is about 4630.2351992096. The cubic root of 21439078 is about 277.8020000329.

The spelling of 21439078 in words is "twenty-one million, four hundred thirty-nine thousand, seventy-eight".