21261162130057 has 2 divisors, whose sum is σ = 21261162130058. Its totient is φ = 21261162130056.

The previous prime is 21261162130051. The next prime is 21261162130067. The reversal of 21261162130057 is 75003126116212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11781019657801 + 9480142472256 = 3432349^2 + 3078984^2 .

It is a cyclic number.

It is not a de Polignac number, because 21261162130057 - 2¹⁹ = 21261161605769 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21261162129998 and 21261162130025.

It is not a weakly prime, because it can be changed into another prime (21261162130051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10630581065028 + 10630581065029.

It is an arithmetic number, because the mean of its divisors is an integer number (10630581065029).

Almost surely, 2^{21261162130057} is an apocalyptic number.

It is an amenable number.

21261162130057 is a deficient number, since it is larger than the sum of its proper divisors (1).

21261162130057 is an equidigital number, since it uses as much as digits as its factorization.

21261162130057 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 30240, while the sum is 37.

Adding to 21261162130057 its reverse (75003126116212), we get a palindrome (96264288246269).

The spelling of 21261162130057 in words is "twenty-one trillion, two hundred sixty-one billion, one hundred sixty-two million, one hundred thirty thousand, fifty-seven".