228621551 has 4 divisors (see below), whose sum is σ = 228654504. Its totient is φ = 228588600.

The previous prime is 228621539. The next prime is 228621553. The reversal of 228621551 is 155126822.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-228621551 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (228621553) 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 3 ways as a sum of consecutive naturals, for example, 1580 + ... + 21441.

It is an arithmetic number, because the mean of its divisors is an integer number (57163626).

Almost surely, 2^228621551 is an apocalyptic number.

228621551 is a deficient number, since it is larger than the sum of its proper divisors (32953).

228621551 is an equidigital number, since it uses as much as digits as its factorization.

228621551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32952.

The product of its digits is 9600, while the sum is 32.

The square root of 228621551 is about 15120.2364730185. The cubic root of 228621551 is about 611.4661061753.

The spelling of 228621551 in words is "two hundred twenty-eight million, six hundred twenty-one thousand, five hundred fifty-one".