221235881 has 2 divisors, whose sum is σ = 221235882. Its totient is φ = 221235880.

The previous prime is 221235869. The next prime is 221235887. The reversal of 221235881 is 188532122.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 213306025 + 7929856 = 14605^2 + 2816^2 .

It is a cyclic number.

It is not a de Polignac number, because 221235881 - 2¹⁰ = 221234857 is a prime.

It is a super-2 number, since 2×221235881² = 97890630083692322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (221235887) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110617940 + 110617941.

It is an arithmetic number, because the mean of its divisors is an integer number (110617941).

Almost surely, 2^221235881 is an apocalyptic number.

It is an amenable number.

221235881 is a deficient number, since it is larger than the sum of its proper divisors (1).

221235881 is an equidigital number, since it uses as much as digits as its factorization.

221235881 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7680, while the sum is 32.

The square root of 221235881 is about 14874.0001680785. Note that the first 3 decimals coincide. The cubic root of 221235881 is about 604.8093846598.

The spelling of 221235881 in words is "two hundred twenty-one million, two hundred thirty-five thousand, eight hundred eighty-one".