203121229991 has 2 divisors, whose sum is σ = 203121229992. Its totient is φ = 203121229990.

The previous prime is 203121229951. The next prime is 203121230009. The reversal of 203121229991 is 199922121302.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-203121229991 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (203121229951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 101560614995 + 101560614996.

It is an arithmetic number, because the mean of its divisors is an integer number (101560614996).

Almost surely, 2^203121229991 is an apocalyptic number.

203121229991 is a deficient number, since it is larger than the sum of its proper divisors (1).

203121229991 is an equidigital number, since it uses as much as digits as its factorization.

203121229991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 34992, while the sum is 41.

The spelling of 203121229991 in words is "two hundred three billion, one hundred twenty-one million, two hundred twenty-nine thousand, nine hundred ninety-one".