21646142 has 12 divisors (see below), whose sum is σ = 37770480. Its totient is φ = 9276876.

The previous prime is 21646139. The next prime is 21646189. The reversal of 21646142 is 24164612.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 110342 + ... + 110537.

It is an arithmetic number, because the mean of its divisors is an integer number (3147540).

Almost surely, 2^21646142 is an apocalyptic number.

21646142 is a deficient number, since it is larger than the sum of its proper divisors (16124338).

21646142 is a wasteful number, since it uses less digits than its factorization.

21646142 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 220895 (or 220888 counting only the distinct ones).

The product of its digits is 2304, while the sum is 26.

The square root of 21646142 is about 4652.5414560216. The cubic root of 21646142 is about 278.6934965608.

The spelling of 21646142 in words is "twenty-one million, six hundred forty-six thousand, one hundred forty-two".