1531026561 has 4 divisors (see below), whose sum is σ = 2041368752. Its totient is φ = 1020684372.

The previous prime is 1531026527. The next prime is 1531026569. The reversal of 1531026561 is 1656201351.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 1531026561 - 2⁷ = 1531026433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1531026569) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 255171091 + ... + 255171096.

It is an arithmetic number, because the mean of its divisors is an integer number (510342188).

Almost surely, 2^1531026561 is an apocalyptic number.

It is an amenable number.

1531026561 is a deficient number, since it is larger than the sum of its proper divisors (510342191).

1531026561 is an equidigital number, since it uses as much as digits as its factorization.

1531026561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 510342190.

The product of its (nonzero) digits is 5400, while the sum is 30.

The square root of 1531026561 is about 39128.3345032727. The cubic root of 1531026561 is about 1152.5530076331.

The spelling of 1531026561 in words is "one billion, five hundred thirty-one million, twenty-six thousand, five hundred sixty-one".