8261976521 has 2 divisors, whose sum is σ = 8261976522. Its totient is φ = 8261976520.

The previous prime is 8261976419. The next prime is 8261976539. The reversal of 8261976521 is 1256791628.

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., 7994326921 + 267649600 = 89411^2 + 16360^2 .

It is a cyclic number.

It is not a de Polignac number, because 8261976521 - 2²² = 8257782217 is a prime.

It is not a weakly prime, because it can be changed into another prime (8261976571) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4130988260 + 4130988261.

It is an arithmetic number, because the mean of its divisors is an integer number (4130988261).

Almost surely, 2^8261976521 is an apocalyptic number.

It is an amenable number.

8261976521 is a deficient number, since it is larger than the sum of its proper divisors (1).

8261976521 is an equidigital number, since it uses as much as digits as its factorization.

8261976521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 362880, while the sum is 47.

The square root of 8261976521 is about 90895.4152914216. The cubic root of 8261976521 is about 2021.5973152423.

The spelling of 8261976521 in words is "eight billion, two hundred sixty-one million, nine hundred seventy-six thousand, five hundred twenty-one".