625372123781 has 2 divisors, whose sum is σ = 625372123782. Its totient is φ = 625372123780.

The previous prime is 625372123771. The next prime is 625372123799. The reversal of 625372123781 is 187321273526.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 623199724900 + 2172398881 = 789430^2 + 46609^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-625372123781 is a prime.

It is a super-2 number, since 2×625372123781² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (625372123741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 312686061890 + 312686061891.

It is an arithmetic number, because the mean of its divisors is an integer number (312686061891).

Almost surely, 2^625372123781 is an apocalyptic number.

It is an amenable number.

625372123781 is a deficient number, since it is larger than the sum of its proper divisors (1).

625372123781 is an equidigital number, since it uses as much as digits as its factorization.

625372123781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 846720, while the sum is 47.

The spelling of 625372123781 in words is "six hundred twenty-five billion, three hundred seventy-two million, one hundred twenty-three thousand, seven hundred eighty-one".