21851043 has 8 divisors (see below), whose sum is σ = 29283408. Its totient is φ = 14493024.

The previous prime is 21851041. The next prime is 21851051. The reversal of 21851043 is 34015812.

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

It is not a de Polignac number, because 21851043 - 2¹ = 21851041 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21851041) 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, 17896 + ... + 19077.

It is an arithmetic number, because the mean of its divisors is an integer number (3660426).

Almost surely, 2^21851043 is an apocalyptic number.

21851043 is a deficient number, since it is larger than the sum of its proper divisors (7432365).

21851043 is a wasteful number, since it uses less digits than its factorization.

21851043 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37173.

The product of its (nonzero) digits is 960, while the sum is 24.

The square root of 21851043 is about 4674.5099208366. The cubic root of 21851043 is about 279.5701013463.

Adding to 21851043 its reverse (34015812), we get a palindrome (55866855).

The spelling of 21851043 in words is "twenty-one million, eight hundred fifty-one thousand, forty-three".