331221220209977 has 2 divisors, whose sum is σ = 331221220209978. Its totient is φ = 331221220209976.

The previous prime is 331221220209973. The next prime is 331221220210007. The reversal of 331221220209977 is 779902022122133.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 324150173397241 + 7071046812736 = 18004171^2 + 2659144^2 .

It is a cyclic number.

It is not a de Polignac number, because 331221220209977 - 2² = 331221220209973 is a prime.

It is not a weakly prime, because it can be changed into another prime (331221220209973) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 165610610104988 + 165610610104989.

It is an arithmetic number, because the mean of its divisors is an integer number (165610610104989).

Almost surely, 2^{331221220209977} is an apocalyptic number.

It is an amenable number.

331221220209977 is a deficient number, since it is larger than the sum of its proper divisors (1).

331221220209977 is an equidigital number, since it uses as much as digits as its factorization.

331221220209977 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1143072, while the sum is 50.

The spelling of 331221220209977 in words is "three hundred thirty-one trillion, two hundred twenty-one billion, two hundred twenty million, two hundred nine thousand, nine hundred seventy-seven".