21347842 has 8 divisors (see below), whose sum is σ = 32044032. Its totient is φ = 10666500.

The previous prime is 21347827. The next prime is 21347863. The reversal of 21347842 is 24874312.

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

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, 1167 + ... + 6637.

It is an arithmetic number, because the mean of its divisors is an integer number (4005504).

Almost surely, 2^21347842 is an apocalyptic number.

21347842 is a deficient number, since it is larger than the sum of its proper divisors (10696190).

21347842 is a wasteful number, since it uses less digits than its factorization.

21347842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7424.

The product of its digits is 10752, while the sum is 31.

The square root of 21347842 is about 4620.3724958059. The cubic root of 21347842 is about 277.4073689149.

The spelling of 21347842 in words is "twenty-one million, three hundred forty-seven thousand, eight hundred forty-two".