8128571261 has 2 divisors, whose sum is σ = 8128571262. Its totient is φ = 8128571260.

The previous prime is 8128571239. The next prime is 8128571281. The reversal of 8128571261 is 1621758218.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5265679225 + 2862892036 = 72565^2 + 53506^2 .

It is a cyclic number.

It is not a de Polignac number, because 8128571261 - 2¹⁴ = 8128554877 is a prime.

It is a super-3 number, since 3×8128571261³ (a number of 31 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8128571221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4064285630 + 4064285631.

It is an arithmetic number, because the mean of its divisors is an integer number (4064285631).

Almost surely, 2^8128571261 is an apocalyptic number.

It is an amenable number.

8128571261 is a deficient number, since it is larger than the sum of its proper divisors (1).

8128571261 is an equidigital number, since it uses as much as digits as its factorization.

8128571261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 53760, while the sum is 41.

The square root of 8128571261 is about 90158.5895020547. The cubic root of 8128571261 is about 2010.6573809933.

The spelling of 8128571261 in words is "eight billion, one hundred twenty-eight million, five hundred seventy-one thousand, two hundred sixty-one".