21010012012091 has 2 divisors, whose sum is σ = 21010012012092. Its totient is φ = 21010012012090.

The previous prime is 21010012012063. The next prime is 21010012012117. The reversal of 21010012012091 is 19021021001012.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21010012012091 is a prime.

It is a super-2 number, since 2×21010012012091² (a number of 27 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (21010012017091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10505006006045 + 10505006006046.

It is an arithmetic number, because the mean of its divisors is an integer number (10505006006046).

Almost surely, 2^{21010012012091} is an apocalyptic number.

21010012012091 is a deficient number, since it is larger than the sum of its proper divisors (1).

21010012012091 is an equidigital number, since it uses as much as digits as its factorization.

21010012012091 is an evil number, because the sum of its binary digits is even.

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

The spelling of 21010012012091 in words is "twenty-one trillion, ten billion, twelve million, twelve thousand, ninety-one".