21667342 has 4 divisors (see below), whose sum is σ = 32501016. Its totient is φ = 10833670.

The previous prime is 21667309. The next prime is 21667351. The reversal of 21667342 is 24376612.

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

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

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, 5416834 + ... + 5416837.

It is an arithmetic number, because the mean of its divisors is an integer number (8125254).

Almost surely, 2^21667342 is an apocalyptic number.

21667342 is a deficient number, since it is larger than the sum of its proper divisors (10833674).

21667342 is a wasteful number, since it uses less digits than its factorization.

21667342 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10833673.

The product of its digits is 12096, while the sum is 31.

The square root of 21667342 is about 4654.8192231278. The cubic root of 21667342 is about 278.7844500177.

The spelling of 21667342 in words is "twenty-one million, six hundred sixty-seven thousand, three hundred forty-two".