21340394 has 8 divisors (see below), whose sum is σ = 32059908. Its totient is φ = 10653760.

The previous prime is 21340387. The next prime is 21340409. The reversal of 21340394 is 49304312.

It can be written as a sum of positive squares in 2 ways, for example, as 17749369 + 3591025 = 4213^2 + 1895^2 .

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

It is a Curzon number.

It is an unprimeable number.

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, 6527 + ... + 9234.

Almost surely, 2^21340394 is an apocalyptic number.

21340394 is a deficient number, since it is larger than the sum of its proper divisors (10719514).

21340394 is a wasteful number, since it uses less digits than its factorization.

21340394 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16440.

The product of its (nonzero) digits is 2592, while the sum is 26.

The square root of 21340394 is about 4619.5664298720. The cubic root of 21340394 is about 277.3751038205.

The spelling of 21340394 in words is "twenty-one million, three hundred forty thousand, three hundred ninety-four".