1215325531 has 16 divisors (see below), whose sum is σ = 1422240768. Its totient is φ = 1017021600.

The previous prime is 1215325523. The next prime is 1215325547. The reversal of 1215325531 is 1355235121.

It is not a de Polignac number, because 1215325531 - 2³ = 1215325523 is a prime.

It is a super-2 number, since 2×1215325531² = 2954032292600863922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1215325531.

It is not an unprimeable number, because it can be changed into a prime (1215325571) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 39321 + ... + 63061.

It is an arithmetic number, because the mean of its divisors is an integer number (88890048).

Almost surely, 2^1215325531 is an apocalyptic number.

1215325531 is a deficient number, since it is larger than the sum of its proper divisors (206915237).

1215325531 is a wasteful number, since it uses less digits than its factorization.

1215325531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23922.

The product of its digits is 4500, while the sum is 28.

The square root of 1215325531 is about 34861.5193444004. The cubic root of 1215325531 is about 1067.1632815232.

The spelling of 1215325531 in words is "one billion, two hundred fifteen million, three hundred twenty-five thousand, five hundred thirty-one".