221148557 has 4 divisors (see below), whose sum is σ = 252741216. Its totient is φ = 189555900.

The previous prime is 221148553. The next prime is 221148559. The reversal of 221148557 is 755841122.

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 221148557 - 2² = 221148553 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221148553) 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, 15796319 + ... + 15796332.

It is an arithmetic number, because the mean of its divisors is an integer number (63185304).

Almost surely, 2^221148557 is an apocalyptic number.

It is an amenable number.

221148557 is a deficient number, since it is larger than the sum of its proper divisors (31592659).

221148557 is an equidigital number, since it uses as much as digits as its factorization.

221148557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31592658.

The product of its digits is 22400, while the sum is 35.

The square root of 221148557 is about 14871.0644205450. The cubic root of 221148557 is about 604.7297994304.

Adding to 221148557 its reverse (755841122), we get a palindrome (976989679).

The spelling of 221148557 in words is "two hundred twenty-one million, one hundred forty-eight thousand, five hundred fifty-seven".