221157166 has 4 divisors (see below), whose sum is σ = 331735752. Its totient is φ = 110578582.

The previous prime is 221157163. The next prime is 221157173. The reversal of 221157166 is 661751122.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 661751122 = 2 ⋅330875561.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221157163) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55289290 + ... + 55289293.

It is an arithmetic number, because the mean of its divisors is an integer number (82933938).

Almost surely, 2^221157166 is an apocalyptic number.

221157166 is a deficient number, since it is larger than the sum of its proper divisors (110578586).

221157166 is a wasteful number, since it uses less digits than its factorization.

221157166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110578585.

The product of its digits is 5040, while the sum is 31.

The square root of 221157166 is about 14871.3538724623. The cubic root of 221157166 is about 604.7376464200.

The spelling of 221157166 in words is "two hundred twenty-one million, one hundred fifty-seven thousand, one hundred sixty-six".