221553949 has 2 divisors, whose sum is σ = 221553950. Its totient is φ = 221553948.

The previous prime is 221553947. The next prime is 221553961. The reversal of 221553949 is 949355122.

221553949 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 213685924 + 7868025 = 14618^2 + 2805^2 .

It is a cyclic number.

It is not a de Polignac number, because 221553949 - 2¹ = 221553947 is a prime.

Together with 221553947, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221553947) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110776974 + 110776975.

It is an arithmetic number, because the mean of its divisors is an integer number (110776975).

Almost surely, 2^221553949 is an apocalyptic number.

It is an amenable number.

221553949 is a deficient number, since it is larger than the sum of its proper divisors (1).

221553949 is an equidigital number, since it uses as much as digits as its factorization.

221553949 is an evil number, because the sum of its binary digits is even.

The product of its digits is 97200, while the sum is 40.

The square root of 221553949 is about 14884.6884078908. The cubic root of 221553949 is about 605.0990881120.

The spelling of 221553949 in words is "two hundred twenty-one million, five hundred fifty-three thousand, nine hundred forty-nine".