21783442 has 8 divisors (see below), whose sum is σ = 33163056. Its totient is φ = 10729092.

The previous prime is 21783431. The next prime is 21783451. The reversal of 21783442 is 24438712.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 81148 + ... + 81415.

It is an arithmetic number, because the mean of its divisors is an integer number (4145382).

Almost surely, 2^21783442 is an apocalyptic number.

21783442 is a deficient number, since it is larger than the sum of its proper divisors (11379614).

21783442 is a wasteful number, since it uses less digits than its factorization.

21783442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 162632.

The product of its digits is 10752, while the sum is 31.

The square root of 21783442 is about 4667.2735081630. The cubic root of 21783442 is about 279.2814996899.

The spelling of 21783442 in words is "twenty-one million, seven hundred eighty-three thousand, four hundred forty-two".