221671801 has 4 divisors (see below), whose sum is σ = 238723492. Its totient is φ = 204620112.

The previous prime is 221671799. The next prime is 221671817. The reversal of 221671801 is 108176122.

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

It can be written as a sum of positive squares in 2 ways, for example, as 51108201 + 170563600 = 7149^2 + 13060^2 .

It is a cyclic number.

It is not a de Polignac number, because 221671801 - 2¹ = 221671799 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 221671801.

It is not an unprimeable number, because it can be changed into a prime (221671831) 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, 8525826 + ... + 8525851.

It is an arithmetic number, because the mean of its divisors is an integer number (59680873).

Almost surely, 2^221671801 is an apocalyptic number.

It is an amenable number.

221671801 is a deficient number, since it is larger than the sum of its proper divisors (17051691).

221671801 is a wasteful number, since it uses less digits than its factorization.

221671801 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17051690.

The product of its (nonzero) digits is 1344, while the sum is 28.

The square root of 221671801 is about 14888.6467148630. The cubic root of 221671801 is about 605.2063599485.

The spelling of 221671801 in words is "two hundred twenty-one million, six hundred seventy-one thousand, eight hundred one".