21123310139 has 2 divisors, whose sum is σ = 21123310140. Its totient is φ = 21123310138.

The previous prime is 21123310133. The next prime is 21123310171. The reversal of 21123310139 is 93101332112.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21123310139 is a prime.

It is not a weakly prime, because it can be changed into another prime (21123310133) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10561655069 + 10561655070.

It is an arithmetic number, because the mean of its divisors is an integer number (10561655070).

Almost surely, 2^21123310139 is an apocalyptic number.

21123310139 is a deficient number, since it is larger than the sum of its proper divisors (1).

21123310139 is an equidigital number, since it uses as much as digits as its factorization.

21123310139 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 972, while the sum is 26.

The spelling of 21123310139 in words is "twenty-one billion, one hundred twenty-three million, three hundred ten thousand, one hundred thirty-nine".