221451949 has 2 divisors, whose sum is σ = 221451950. Its totient is φ = 221451948.

The previous prime is 221451929. The next prime is 221451959. The reversal of 221451949 is 949154122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 180042724 + 41409225 = 13418^2 + 6435^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221451949 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221451929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110725974 + 110725975.

It is an arithmetic number, because the mean of its divisors is an integer number (110725975).

Almost surely, 2^221451949 is an apocalyptic number.

It is an amenable number.

221451949 is a deficient number, since it is larger than the sum of its proper divisors (1).

221451949 is an equidigital number, since it uses as much as digits as its factorization.

221451949 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 25920, while the sum is 37.

The square root of 221451949 is about 14881.2616736619. The cubic root of 221451949 is about 605.0062144479.

The spelling of 221451949 in words is "two hundred twenty-one million, four hundred fifty-one thousand, nine hundred forty-nine".