1531000391 has 2 divisors, whose sum is σ = 1531000392. Its totient is φ = 1531000390.

The previous prime is 1531000369. The next prime is 1531000403. The reversal of 1531000391 is 1930001351.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1531000391 - 2⁶ = 1531000327 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1531000351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 765500195 + 765500196.

It is an arithmetic number, because the mean of its divisors is an integer number (765500196).

Almost surely, 2^1531000391 is an apocalyptic number.

1531000391 is a deficient number, since it is larger than the sum of its proper divisors (1).

1531000391 is an equidigital number, since it uses as much as digits as its factorization.

1531000391 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 405, while the sum is 23.

The square root of 1531000391 is about 39128.0000894500. Note that the first 4 decimals coincide. The cubic root of 1531000391 is about 1152.5464406919.

The spelling of 1531000391 in words is "one billion, five hundred thirty-one million, three hundred ninety-one", and thus it is an aban number.