221605557157 has 2 divisors, whose sum is σ = 221605557158. Its totient is φ = 221605557156.

The previous prime is 221605557137. The next prime is 221605557197. The reversal of 221605557157 is 751755506122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 120325040641 + 101280516516 = 346879^2 + 318246^2 .

It is a cyclic number.

It is not a de Polignac number, because 221605557157 - 2⁷ = 221605557029 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221605557137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110802778578 + 110802778579.

It is an arithmetic number, because the mean of its divisors is an integer number (110802778579).

Almost surely, 2^221605557157 is an apocalyptic number.

It is an amenable number.

221605557157 is a deficient number, since it is larger than the sum of its proper divisors (1).

221605557157 is an equidigital number, since it uses as much as digits as its factorization.

221605557157 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 735000, while the sum is 46.

The spelling of 221605557157 in words is "two hundred twenty-one billion, six hundred five million, five hundred fifty-seven thousand, one hundred fifty-seven".