1021121200991 has 2 divisors, whose sum is σ = 1021121200992. Its totient is φ = 1021121200990.

The previous prime is 1021121200933. The next prime is 1021121201029. The reversal of 1021121200991 is 1990021211201.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1021121200991 - 2¹⁴ = 1021121184607 is a prime.

It is a super-2 number, since 2×1021121200991² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1021121205991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 510560600495 + 510560600496.

It is an arithmetic number, because the mean of its divisors is an integer number (510560600496).

Almost surely, 2^{1021121200991} is an apocalyptic number.

1021121200991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1021121200991 is an equidigital number, since it uses as much as digits as its factorization.

1021121200991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 648, while the sum is 29.

The spelling of 1021121200991 in words is "one trillion, twenty-one billion, one hundred twenty-one million, two hundred thousand, nine hundred ninety-one".