425664523415981 has 2 divisors, whose sum is σ = 425664523415982. Its totient is φ = 425664523415980.

The previous prime is 425664523415909. The next prime is 425664523416029. The reversal of 425664523415981 is 189514325466524.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 371559010049956 + 54105513366025 = 19275866^2 + 7355645^2 .

It is a cyclic number.

It is not a de Polignac number, because 425664523415981 - 2³⁴ = 425647343546797 is a prime.

It is a super-2 number, since 2×425664523415981² (a number of 30 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (425664523415581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 212832261707990 + 212832261707991.

It is an arithmetic number, because the mean of its divisors is an integer number (212832261707991).

Almost surely, 2^{425664523415981} is an apocalyptic number.

It is an amenable number.

425664523415981 is a deficient number, since it is larger than the sum of its proper divisors (1).

425664523415981 is an equidigital number, since it uses as much as digits as its factorization.

425664523415981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 248832000, while the sum is 65.

The spelling of 425664523415981 in words is "four hundred twenty-five trillion, six hundred sixty-four billion, five hundred twenty-three million, four hundred fifteen thousand, nine hundred eighty-one".