21850081 has 8 divisors (see below), whose sum is σ = 23882400. Its totient is φ = 19825440.

The previous prime is 21850061. The next prime is 21850093. The reversal of 21850081 is 18005812.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21850081 is a prime.

It is a super-2 number, since 2×21850081² = 954852079413122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21850051) 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, 5205 + ... + 8413.

It is an arithmetic number, because the mean of its divisors is an integer number (2985300).

Almost surely, 2^21850081 is an apocalyptic number.

It is an amenable number.

21850081 is a deficient number, since it is larger than the sum of its proper divisors (2032319).

21850081 is a wasteful number, since it uses less digits than its factorization.

21850081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3839.

The product of its (nonzero) digits is 640, while the sum is 25.

The square root of 21850081 is about 4674.4070212167. The cubic root of 21850081 is about 279.5659985615.

Adding to 21850081 its reverse (18005812), we get a palindrome (39855893).

The spelling of 21850081 in words is "twenty-one million, eight hundred fifty thousand, eighty-one".