399271006261 has 2 divisors, whose sum is σ = 399271006262. Its totient is φ = 399271006260.

The previous prime is 399271006201. The next prime is 399271006319. The reversal of 399271006261 is 162600172993.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 332761691025 + 66509315236 = 576855^2 + 257894^2 .

It is a cyclic number.

It is not a de Polignac number, because 399271006261 - 2⁷ = 399271006133 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (399271006201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199635503130 + 199635503131.

It is an arithmetic number, because the mean of its divisors is an integer number (199635503131).

Almost surely, 2^399271006261 is an apocalyptic number.

It is an amenable number.

399271006261 is a deficient number, since it is larger than the sum of its proper divisors (1).

399271006261 is an equidigital number, since it uses as much as digits as its factorization.

399271006261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 244944, while the sum is 46.

The spelling of 399271006261 in words is "three hundred ninety-nine billion, two hundred seventy-one million, six thousand, two hundred sixty-one".