21012210139 has 2 divisors, whose sum is σ = 21012210140. Its totient is φ = 21012210138.

The previous prime is 21012210113. The next prime is 21012210169. The reversal of 21012210139 is 93101221012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21012210139 - 2²¹ = 21010112987 is a prime.

It is not a weakly prime, because it can be changed into another prime (21012210169) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506105069 + 10506105070.

It is an arithmetic number, because the mean of its divisors is an integer number (10506105070).

Almost surely, 2^21012210139 is an apocalyptic number.

21012210139 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012210139 is an equidigital number, since it uses as much as digits as its factorization.

21012210139 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 216, while the sum is 22.

The spelling of 21012210139 in words is "twenty-one billion, twelve million, two hundred ten thousand, one hundred thirty-nine".