221333137 has 4 divisors (see below), whose sum is σ = 221410800. Its totient is φ = 221255476.

The previous prime is 221333089. The next prime is 221333143. The reversal of 221333137 is 731333122.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 221333137 - 2¹⁹ = 220808849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221333197) 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, 34387 + ... + 40312.

It is an arithmetic number, because the mean of its divisors is an integer number (55352700).

Almost surely, 2^221333137 is an apocalyptic number.

It is an amenable number.

221333137 is a deficient number, since it is larger than the sum of its proper divisors (77663).

221333137 is an equidigital number, since it uses as much as digits as its factorization.

221333137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77662.

The product of its digits is 2268, while the sum is 25.

The square root of 221333137 is about 14877.2691378492. The cubic root of 221333137 is about 604.8979970555.

Adding to 221333137 its reverse (731333122), we get a palindrome (952666259).

The spelling of 221333137 in words is "two hundred twenty-one million, three hundred thirty-three thousand, one hundred thirty-seven".