1012212001991 has 2 divisors, whose sum is σ = 1012212001992. Its totient is φ = 1012212001990.

The previous prime is 1012212001961. The next prime is 1012212002023. The reversal of 1012212001991 is 1991002122101.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1012212001991 - 2¹⁰ = 1012212000967 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1012212001951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 506106000995 + 506106000996.

It is an arithmetic number, because the mean of its divisors is an integer number (506106000996).

Almost surely, 2^{1012212001991} is an apocalyptic number.

1012212001991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1012212001991 is an equidigital number, since it uses as much as digits as its factorization.

1012212001991 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 1012212001991 in words is "one trillion, twelve billion, two hundred twelve million, one thousand, nine hundred ninety-one".