1200001021091 has 2 divisors, whose sum is σ = 1200001021092. Its totient is φ = 1200001021090.

The previous prime is 1200001021061. The next prime is 1200001021111. The reversal of 1200001021091 is 1901201000021.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1200001021091 - 2³⁸ = 925123114147 is a prime.

It is a super-3 number, since 3×1200001021091³ (a number of 37 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (1200001021061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 600000510545 + 600000510546.

It is an arithmetic number, because the mean of its divisors is an integer number (600000510546).

Almost surely, 2^{1200001021091} is an apocalyptic number.

1200001021091 is a deficient number, since it is larger than the sum of its proper divisors (1).

1200001021091 is an equidigital number, since it uses as much as digits as its factorization.

1200001021091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36, while the sum is 17.

The spelling of 1200001021091 in words is "one trillion, two hundred billion, one million, twenty-one thousand, ninety-one".