21849047 has 4 divisors (see below), whose sum is σ = 23835336. Its totient is φ = 19862760.

The previous prime is 21849013. The next prime is 21849049. The reversal of 21849047 is 74094812.

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

It is a cyclic number.

It is not a de Polignac number, because 21849047 - 2¹⁰ = 21848023 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21848998 and 21849016.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21849049) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 993128 + ... + 993149.

It is an arithmetic number, because the mean of its divisors is an integer number (5958834).

Almost surely, 2^21849047 is an apocalyptic number.

21849047 is a deficient number, since it is larger than the sum of its proper divisors (1986289).

21849047 is a wasteful number, since it uses less digits than its factorization.

21849047 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1986288.

The product of its (nonzero) digits is 16128, while the sum is 35.

The square root of 21849047 is about 4674.2964176441. The cubic root of 21849047 is about 279.5615885732.

The spelling of 21849047 in words is "twenty-one million, eight hundred forty-nine thousand, forty-seven".