221002201991 has 2 divisors, whose sum is σ = 221002201992. Its totient is φ = 221002201990.

The previous prime is 221002201957. The next prime is 221002202009. The reversal of 221002201991 is 199102200122.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221002201991 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221002201291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110501100995 + 110501100996.

It is an arithmetic number, because the mean of its divisors is an integer number (110501100996).

Almost surely, 2^221002201991 is an apocalyptic number.

221002201991 is a deficient number, since it is larger than the sum of its proper divisors (1).

221002201991 is an equidigital number, since it uses as much as digits as its factorization.

221002201991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 29.

The spelling of 221002201991 in words is "two hundred twenty-one billion, two million, two hundred one thousand, nine hundred ninety-one".