21870041 has 8 divisors (see below), whose sum is σ = 23289120. Its totient is φ = 20465728.

The previous prime is 21870029. The next prime is 21870047. The reversal of 21870041 is 14007812.

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 21870041 - 2¹⁸ = 21607897 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21869989 and 21870016.

It is not an unprimeable number, because it can be changed into a prime (21870047) 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, 551 + ... + 6636.

It is an arithmetic number, because the mean of its divisors is an integer number (2911140).

Almost surely, 2^21870041 is an apocalyptic number.

It is an amenable number.

21870041 is a deficient number, since it is larger than the sum of its proper divisors (1419079).

21870041 is a wasteful number, since it uses less digits than its factorization.

21870041 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7383.

The product of its (nonzero) digits is 448, while the sum is 23.

The square root of 21870041 is about 4676.5415640193. The cubic root of 21870041 is about 279.6511002909.

Adding to 21870041 its reverse (14007812), we get a palindrome (35877853).

The spelling of 21870041 in words is "twenty-one million, eight hundred seventy thousand, forty-one".