21673942 has 4 divisors (see below), whose sum is σ = 32510916. Its totient is φ = 10836970.

The previous prime is 21673921. The next prime is 21673961. The reversal of 21673942 is 24937612.

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

It is a junction number, because it is equal to n+sod(n) for n = 21673898 and 21673907.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5418484 + ... + 5418487.

It is an arithmetic number, because the mean of its divisors is an integer number (8127729).

Almost surely, 2^21673942 is an apocalyptic number.

21673942 is a deficient number, since it is larger than the sum of its proper divisors (10836974).

21673942 is a wasteful number, since it uses less digits than its factorization.

21673942 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10836973.

The product of its digits is 18144, while the sum is 34.

The square root of 21673942 is about 4655.5281118258. The cubic root of 21673942 is about 278.8127536060.

The spelling of 21673942 in words is "twenty-one million, six hundred seventy-three thousand, nine hundred forty-two".