21749342 has 8 divisors (see below), whose sum is σ = 32659032. Its totient is φ = 10863000.

The previous prime is 21749323. The next prime is 21749353. The reversal of 21749342 is 24394712.

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

It is a junction number, because it is equal to n+sod(n) for n = 21749299 and 21749308.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3284 + ... + 7367.

It is an arithmetic number, because the mean of its divisors is an integer number (4082379).

Almost surely, 2^21749342 is an apocalyptic number.

21749342 is a deficient number, since it is larger than the sum of its proper divisors (10909690).

21749342 is a wasteful number, since it uses less digits than its factorization.

21749342 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11674.

The product of its digits is 12096, while the sum is 32.

The square root of 21749342 is about 4663.6189810061. The cubic root of 21749342 is about 279.1356936405.

The spelling of 21749342 in words is "twenty-one million, seven hundred forty-nine thousand, three hundred forty-two".