221813790997 has 2 divisors, whose sum is σ = 221813790998. Its totient is φ = 221813790996.

The previous prime is 221813790973. The next prime is 221813791009. The reversal of 221813790997 is 799097318122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 190786377681 + 31027413316 = 436791^2 + 176146^2 .

It is a cyclic number.

It is not a de Polignac number, because 221813790997 - 2³⁵ = 187454052629 is a prime.

It is a super-3 number, since 3×221813790997³ (a number of 35 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221813790917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110906895498 + 110906895499.

It is an arithmetic number, because the mean of its divisors is an integer number (110906895499).

Almost surely, 2^221813790997 is an apocalyptic number.

It is an amenable number.

221813790997 is a deficient number, since it is larger than the sum of its proper divisors (1).

221813790997 is an equidigital number, since it uses as much as digits as its factorization.

221813790997 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3429216, while the sum is 58.

The spelling of 221813790997 in words is "two hundred twenty-one billion, eight hundred thirteen million, seven hundred ninety thousand, nine hundred ninety-seven".