221657222249251 has 2 divisors, whose sum is σ = 221657222249252. Its totient is φ = 221657222249250.

The previous prime is 221657222249201. The next prime is 221657222249269. The reversal of 221657222249251 is 152942222756122.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 221657222249251 - 2⁷ = 221657222249123 is a prime.

It is a super-4 number, since 4×221657222249251⁴ (a number of 58 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (221657222249201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110828611124625 + 110828611124626.

It is an arithmetic number, because the mean of its divisors is an integer number (110828611124626).

Almost surely, 2^{221657222249251} is an apocalyptic number.

221657222249251 is a deficient number, since it is larger than the sum of its proper divisors (1).

221657222249251 is an equidigital number, since it uses as much as digits as its factorization.

221657222249251 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4838400, while the sum is 52.

The spelling of 221657222249251 in words is "two hundred twenty-one trillion, six hundred fifty-seven billion, two hundred twenty-two million, two hundred forty-nine thousand, two hundred fifty-one".