221001201977 has 2 divisors, whose sum is σ = 221001201978. Its totient is φ = 221001201976.

The previous prime is 221001201959. The next prime is 221001202003. The reversal of 221001201977 is 779102100122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 220614332416 + 386869561 = 469696^2 + 19669^2 .

It is a cyclic number.

It is not a de Polignac number, because 221001201977 - 2¹² = 221001197881 is a prime.

It is not a weakly prime, because it can be changed into another prime (221001200977) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110500600988 + 110500600989.

It is an arithmetic number, because the mean of its divisors is an integer number (110500600989).

Almost surely, 2^221001201977 is an apocalyptic number.

It is an amenable number.

221001201977 is a deficient number, since it is larger than the sum of its proper divisors (1).

221001201977 is an equidigital number, since it uses as much as digits as its factorization.

221001201977 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3528, while the sum is 32.

The spelling of 221001201977 in words is "two hundred twenty-one billion, one million, two hundred one thousand, nine hundred seventy-seven".