20121021012139 has 2 divisors, whose sum is σ = 20121021012140. Its totient is φ = 20121021012138.

The previous prime is 20121021012041. The next prime is 20121021012149. The reversal of 20121021012139 is 93121012012102.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20121021012139 - 2⁹ = 20121021011627 is a prime.

It is not a weakly prime, because it can be changed into another prime (20121021012149) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10060510506069 + 10060510506070.

It is an arithmetic number, because the mean of its divisors is an integer number (10060510506070).

Almost surely, 2^{20121021012139} is an apocalyptic number.

20121021012139 is a deficient number, since it is larger than the sum of its proper divisors (1).

20121021012139 is an equidigital number, since it uses as much as digits as its factorization.

20121021012139 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 432, while the sum is 25.

The spelling of 20121021012139 in words is "twenty trillion, one hundred twenty-one billion, twenty-one million, twelve thousand, one hundred thirty-nine".