8261721067 has 2 divisors, whose sum is σ = 8261721068. Its totient is φ = 8261721066.

The previous prime is 8261721029. The next prime is 8261721079. The reversal of 8261721067 is 7601271628.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 8261721067 - 2²⁷ = 8127503339 is a prime.

It is not a weakly prime, because it can be changed into another prime (8261721007) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4130860533 + 4130860534.

It is an arithmetic number, because the mean of its divisors is an integer number (4130860534).

Almost surely, 2^8261721067 is an apocalyptic number.

8261721067 is a deficient number, since it is larger than the sum of its proper divisors (1).

8261721067 is an equidigital number, since it uses as much as digits as its factorization.

8261721067 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 56448, while the sum is 40.

The square root of 8261721067 is about 90894.0100721714. The cubic root of 8261721067 is about 2021.5764796129.

It can be divided in two parts, 82617 and 21067, that added together give a square (103684 = 322²).

The spelling of 8261721067 in words is "eight billion, two hundred sixty-one million, seven hundred twenty-one thousand, sixty-seven".