21420121039 has 2 divisors, whose sum is σ = 21420121040. Its totient is φ = 21420121038.

The previous prime is 21420121003. The next prime is 21420121061. The reversal of 21420121039 is 93012102412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21420121039 - 2¹⁵ = 21420088271 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21420121939) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10710060519 + 10710060520.

It is an arithmetic number, because the mean of its divisors is an integer number (10710060520).

Almost surely, 2^21420121039 is an apocalyptic number.

21420121039 is a deficient number, since it is larger than the sum of its proper divisors (1).

21420121039 is an equidigital number, since it uses as much as digits as its factorization.

21420121039 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 25.

The spelling of 21420121039 in words is "twenty-one billion, four hundred twenty million, one hundred twenty-one thousand, thirty-nine".