221525041618949 has 2 divisors, whose sum is σ = 221525041618950. Its totient is φ = 221525041618948.

The previous prime is 221525041618919. The next prime is 221525041619027. The reversal of 221525041618949 is 949816140525122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 158877705808900 + 62647335810049 = 12604670^2 + 7915007^2 .

It is a cyclic number.

It is not a de Polignac number, because 221525041618949 - 2¹² = 221525041614853 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221525041618919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110762520809474 + 110762520809475.

It is an arithmetic number, because the mean of its divisors is an integer number (110762520809475).

Almost surely, 2^{221525041618949} is an apocalyptic number.

It is an amenable number.

221525041618949 is a deficient number, since it is larger than the sum of its proper divisors (1).

221525041618949 is an equidigital number, since it uses as much as digits as its factorization.

221525041618949 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12441600, while the sum is 59.

The spelling of 221525041618949 in words is "two hundred twenty-one trillion, five hundred twenty-five billion, forty-one million, six hundred eighteen thousand, nine hundred forty-nine".