21142111493 has 2 divisors, whose sum is σ = 21142111494. Its totient is φ = 21142111492.

The previous prime is 21142111477. The next prime is 21142111517. The reversal of 21142111493 is 39411124112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18175893124 + 2966218369 = 134818^2 + 54463^2 .

It is a cyclic number.

It is not a de Polignac number, because 21142111493 - 2⁴ = 21142111477 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21142111423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10571055746 + 10571055747.

It is an arithmetic number, because the mean of its divisors is an integer number (10571055747).

Almost surely, 2^21142111493 is an apocalyptic number.

It is an amenable number.

21142111493 is a deficient number, since it is larger than the sum of its proper divisors (1).

21142111493 is an equidigital number, since it uses as much as digits as its factorization.

21142111493 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1728, while the sum is 29.

The spelling of 21142111493 in words is "twenty-one billion, one hundred forty-two million, one hundred eleven thousand, four hundred ninety-three".