1305215531 has 2 divisors, whose sum is σ = 1305215532. Its totient is φ = 1305215530.

The previous prime is 1305215503. The next prime is 1305215551. The reversal of 1305215531 is 1355125031.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1305215531 - 2⁶ = 1305215467 is a prime.

It is a super-2 number, since 2×1305215531² = 3407175164727223922, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1305215531.

It is not a weakly prime, because it can be changed into another prime (1305215501) 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 as a sum of consecutive naturals, namely, 652607765 + 652607766.

It is an arithmetic number, because the mean of its divisors is an integer number (652607766).

Almost surely, 2^1305215531 is an apocalyptic number.

1305215531 is a deficient number, since it is larger than the sum of its proper divisors (1).

1305215531 is an equidigital number, since it uses as much as digits as its factorization.

1305215531 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2250, while the sum is 26.

The square root of 1305215531 is about 36127.7667591010. The cubic root of 1305215531 is about 1092.8504723116.

The spelling of 1305215531 in words is "one billion, three hundred five million, two hundred fifteen thousand, five hundred thirty-one".