8451331561 has 2 divisors, whose sum is σ = 8451331562. Its totient is φ = 8451331560.

The previous prime is 8451331543. The next prime is 8451331621. The reversal of 8451331561 is 1651331548.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7782591961 + 668739600 = 88219^2 + 25860^2 .

It is a cyclic number.

It is not a de Polignac number, because 8451331561 - 2⁵ = 8451331529 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 8451331561.

It is not a weakly prime, because it can be changed into another prime (8451331501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4225665780 + 4225665781.

It is an arithmetic number, because the mean of its divisors is an integer number (4225665781).

Almost surely, 2^8451331561 is an apocalyptic number.

It is an amenable number.

8451331561 is a deficient number, since it is larger than the sum of its proper divisors (1).

8451331561 is an equidigital number, since it uses as much as digits as its factorization.

8451331561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 43200, while the sum is 37.

The square root of 8451331561 is about 91931.1240059644. The cubic root of 8451331561 is about 2036.9250386956.

The spelling of 8451331561 in words is "eight billion, four hundred fifty-one million, three hundred thirty-one thousand, five hundred sixty-one".