51111051613 has 2 divisors, whose sum is σ = 51111051614. Its totient is φ = 51111051612.

The previous prime is 51111051611. The next prime is 51111051619. The reversal of 51111051613 is 31615011115.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 44970291844 + 6140759769 = 212062^2 + 78363^2 .

It is a cyclic number.

It is not a de Polignac number, because 51111051613 - 2¹ = 51111051611 is a prime.

It is a super-2 number, since 2×51111051613² (a number of 22 digits) contains 22 as substring.

Together with 51111051611, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51111051611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25555525806 + 25555525807.

It is an arithmetic number, because the mean of its divisors is an integer number (25555525807).

Almost surely, 2^51111051613 is an apocalyptic number.

It is an amenable number.

51111051613 is a deficient number, since it is larger than the sum of its proper divisors (1).

51111051613 is an equidigital number, since it uses as much as digits as its factorization.

51111051613 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 450, while the sum is 25.

Adding to 51111051613 its reverse (31615011115), we get a palindrome (82726062728).

The spelling of 51111051613 in words is "fifty-one billion, one hundred eleven million, fifty-one thousand, six hundred thirteen".