21782423 has 8 divisors (see below), whose sum is σ = 24838128. Its totient is φ = 18923904.

The previous prime is 21782419. The next prime is 21782447. The reversal of 21782423 is 32428712.

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

It is a cyclic number.

It is not a de Polignac number, because 21782423 - 2² = 21782419 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21782473) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 49061 + ... + 49502.

It is an arithmetic number, because the mean of its divisors is an integer number (3104766).

Almost surely, 2^21782423 is an apocalyptic number.

21782423 is a deficient number, since it is larger than the sum of its proper divisors (3055705).

21782423 is a wasteful number, since it uses less digits than its factorization.

21782423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98593.

The product of its digits is 5376, while the sum is 29.

The square root of 21782423 is about 4667.1643425103. The cubic root of 21782423 is about 279.2771448182.

The spelling of 21782423 in words is "twenty-one million, seven hundred eighty-two thousand, four hundred twenty-three".