221438137 has 4 divisors (see below), whose sum is σ = 224557056. Its totient is φ = 218319220.

The previous prime is 221438117. The next prime is 221438143. The reversal of 221438137 is 731834122.

221438137 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 221438137 - 2¹⁵ = 221405369 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221438099 and 221438108.

It is not an unprimeable number, because it can be changed into a prime (221438117) 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, 1559353 + ... + 1559494.

It is an arithmetic number, because the mean of its divisors is an integer number (56139264).

Almost surely, 2^221438137 is an apocalyptic number.

It is an amenable number.

221438137 is a deficient number, since it is larger than the sum of its proper divisors (3118919).

221438137 is an equidigital number, since it uses as much as digits as its factorization.

221438137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3118918.

The product of its digits is 8064, while the sum is 31.

The square root of 221438137 is about 14880.7975928712. The cubic root of 221438137 is about 604.9936360690.

The spelling of 221438137 in words is "two hundred twenty-one million, four hundred thirty-eight thousand, one hundred thirty-seven".