1215005531 has 2 divisors, whose sum is σ = 1215005532. Its totient is φ = 1215005530.

The previous prime is 1215005527. The next prime is 1215005551. The reversal of 1215005531 is 1355005121.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1215005531 - 2² = 1215005527 is a prime.

It is a super-2 number, since 2×1215005531² = 2952476880721183922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 1215005497 and 1215005506.

It is not a weakly prime, because it can be changed into another prime (1215005551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 607502765 + 607502766.

It is an arithmetic number, because the mean of its divisors is an integer number (607502766).

Almost surely, 2^1215005531 is an apocalyptic number.

1215005531 is a deficient number, since it is larger than the sum of its proper divisors (1).

1215005531 is an equidigital number, since it uses as much as digits as its factorization.

1215005531 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 750, while the sum is 23.

The square root of 1215005531 is about 34856.9294545575. The cubic root of 1215005531 is about 1067.0696105361.

The spelling of 1215005531 in words is "one billion, two hundred fifteen million, five thousand, five hundred thirty-one".