51720118573 has 2 divisors, whose sum is σ = 51720118574. Its totient is φ = 51720118572.

The previous prime is 51720118547. The next prime is 51720118661. The reversal of 51720118573 is 37581102715.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 46271021449 + 5449097124 = 215107^2 + 73818^2 .

It is a cyclic number.

It is not a de Polignac number, because 51720118573 - 2⁹ = 51720118061 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51720118543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25860059286 + 25860059287.

It is an arithmetic number, because the mean of its divisors is an integer number (25860059287).

Almost surely, 2^51720118573 is an apocalyptic number.

It is an amenable number.

51720118573 is a deficient number, since it is larger than the sum of its proper divisors (1).

51720118573 is an equidigital number, since it uses as much as digits as its factorization.

51720118573 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 58800, while the sum is 40.

The spelling of 51720118573 in words is "fifty-one billion, seven hundred twenty million, one hundred eighteen thousand, five hundred seventy-three".