21673142 has 4 divisors (see below), whose sum is σ = 32509716. Its totient is φ = 10836570.

The previous prime is 21673139. The next prime is 21673159. The reversal of 21673142 is 24137612.

It is a semiprime because it is the product of two primes.

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 as a sum of consecutive naturals, namely, 5418284 + ... + 5418287.

It is an arithmetic number, because the mean of its divisors is an integer number (8127429).

Almost surely, 2^21673142 is an apocalyptic number.

21673142 is a deficient number, since it is larger than the sum of its proper divisors (10836574).

21673142 is a wasteful number, since it uses less digits than its factorization.

21673142 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10836573.

The product of its digits is 2016, while the sum is 26.

The square root of 21673142 is about 4655.4421916720. The cubic root of 21673142 is about 278.8093231741.

The spelling of 21673142 in words is "twenty-one million, six hundred seventy-three thousand, one hundred forty-two".