1531985501 has 2 divisors, whose sum is σ = 1531985502. Its totient is φ = 1531985500.

The previous prime is 1531985489. The next prime is 1531985503. The reversal of 1531985501 is 1055891351.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1476557476 + 55428025 = 38426^2 + 7445^2 .

It is a cyclic number.

It is not a de Polignac number, because 1531985501 - 2¹⁰ = 1531984477 is a prime.

Together with 1531985503, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1531985503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 765992750 + 765992751.

It is an arithmetic number, because the mean of its divisors is an integer number (765992751).

Almost surely, 2^1531985501 is an apocalyptic number.

It is an amenable number.

1531985501 is a deficient number, since it is larger than the sum of its proper divisors (1).

1531985501 is an equidigital number, since it uses as much as digits as its factorization.

1531985501 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 27000, while the sum is 38.

The square root of 1531985501 is about 39140.5863650508. The cubic root of 1531985501 is about 1152.7935866321.

The spelling of 1531985501 in words is "one billion, five hundred thirty-one million, nine hundred eighty-five thousand, five hundred one".