221164251 has 32 divisors (see below), whose sum is σ = 383643648. Its totient is φ = 109892640.

The previous prime is 221164201. The next prime is 221164259. The reversal of 221164251 is 152461122.

It is not a de Polignac number, because 221164251 - 2¹⁴ = 221147867 is a prime.

It is not an unprimeable number, because it can be changed into a prime (221164259) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 15501 + ... + 26126.

It is an arithmetic number, because the mean of its divisors is an integer number (11988864).

Almost surely, 2^221164251 is an apocalyptic number.

221164251 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

221164251 is a deficient number, since it is larger than the sum of its proper divisors (162479397).

221164251 is a wasteful number, since it uses less digits than its factorization.

221164251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41671.

The product of its digits is 960, while the sum is 24.

The square root of 221164251 is about 14871.5920802045. The cubic root of 221164251 is about 604.7441041511.

The spelling of 221164251 in words is "two hundred twenty-one million, one hundred sixty-four thousand, two hundred fifty-one".