221800851 has 24 divisors (see below), whose sum is σ = 339056640. Its totient is φ = 139330800.

The previous prime is 221800841. The next prime is 221800861. The reversal of 221800851 is 158008122.

221800851 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (221800841) and next prime (221800861).

It is not a de Polignac number, because 221800851 - 2⁷ = 221800723 is a prime.

It is not an unprimeable number, because it can be changed into a prime (221800841) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 29266 + ... + 36056.

It is an arithmetic number, because the mean of its divisors is an integer number (14127360).

Almost surely, 2^221800851 is an apocalyptic number.

221800851 is a deficient number, since it is larger than the sum of its proper divisors (117255789).

221800851 is a wasteful number, since it uses less digits than its factorization.

221800851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7007 (or 7004 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 27.

The square root of 221800851 is about 14892.9799234404. The cubic root of 221800851 is about 605.3237808822.

Adding to 221800851 its reverse (158008122), we get a palindrome (379808973).

The spelling of 221800851 in words is "two hundred twenty-one million, eight hundred thousand, eight hundred fifty-one".