1531562561 has 2 divisors, whose sum is σ = 1531562562. Its totient is φ = 1531562560.

The previous prime is 1531562531. The next prime is 1531562573. The reversal of 1531562561 is 1652651351.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1386817600 + 144744961 = 37240^2 + 12031^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1531562561 is a prime.

It is not a weakly prime, because it can be changed into another prime (1531562531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 765781280 + 765781281.

It is an arithmetic number, because the mean of its divisors is an integer number (765781281).

Almost surely, 2^1531562561 is an apocalyptic number.

It is an amenable number.

1531562561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1531562561 is an equidigital number, since it uses as much as digits as its factorization.

1531562561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 27000, while the sum is 35.

The square root of 1531562561 is about 39135.1831604248. The cubic root of 1531562561 is about 1152.6874917651.

The spelling of 1531562561 in words is "one billion, five hundred thirty-one million, five hundred sixty-two thousand, five hundred sixty-one".