21365023651079 has 2 divisors, whose sum is σ = 21365023651080. Its totient is φ = 21365023651078.

The previous prime is 21365023651043. The next prime is 21365023651109. The reversal of 21365023651079 is 97015632056312.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21365023651079 - 2²⁴ = 21365006873863 is a prime.

It is a super-2 number, since 2×21365023651079² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21365023651379) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10682511825539 + 10682511825540.

It is an arithmetic number, because the mean of its divisors is an integer number (10682511825540).

Almost surely, 2^{21365023651079} is an apocalyptic number.

21365023651079 is a deficient number, since it is larger than the sum of its proper divisors (1).

21365023651079 is an equidigital number, since it uses as much as digits as its factorization.

21365023651079 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2041200, while the sum is 50.

The spelling of 21365023651079 in words is "twenty-one trillion, three hundred sixty-five billion, twenty-three million, six hundred fifty-one thousand, seventy-nine".