1021002112091 has 4 divisors (see below), whose sum is σ = 1099540736112. Its totient is φ = 942463488072.

The previous prime is 1021002112087. The next prime is 1021002112139. The reversal of 1021002112091 is 1902112001201.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1021002112091 - 2² = 1021002112087 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1021002102091) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39269311991 + ... + 39269312016.

It is an arithmetic number, because the mean of its divisors is an integer number (274885184028).

Almost surely, 2^{1021002112091} is an apocalyptic number.

1021002112091 is a deficient number, since it is larger than the sum of its proper divisors (78538624021).

1021002112091 is an equidigital number, since it uses as much as digits as its factorization.

1021002112091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78538624020.

The product of its (nonzero) digits is 72, while the sum is 20.

Adding to 1021002112091 its reverse (1902112001201), we get a palindrome (2923114113292).

The spelling of 1021002112091 in words is "one trillion, twenty-one billion, two million, one hundred twelve thousand, ninety-one".