61713268021 has 2 divisors, whose sum is σ = 61713268022. Its totient is φ = 61713268020.

The previous prime is 61713267991. The next prime is 61713268027. The reversal of 61713268021 is 12086231716.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 32842500625 + 28870767396 = 181225^2 + 169914^2 .

It is a cyclic number.

It is not a de Polignac number, because 61713268021 - 2¹¹ = 61713265973 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61713268027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30856634010 + 30856634011.

It is an arithmetic number, because the mean of its divisors is an integer number (30856634011).

Almost surely, 2^61713268021 is an apocalyptic number.

It is an amenable number.

61713268021 is a deficient number, since it is larger than the sum of its proper divisors (1).

61713268021 is an equidigital number, since it uses as much as digits as its factorization.

61713268021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24192, while the sum is 37.

Adding to 61713268021 its reverse (12086231716), we get a palindrome (73799499737).

The spelling of 61713268021 in words is "sixty-one billion, seven hundred thirteen million, two hundred sixty-eight thousand, twenty-one".