1215511145 has 8 divisors (see below), whose sum is σ = 1459066056. Its totient is φ = 972107136.

The previous prime is 1215511123. The next prime is 1215511159. The reversal of 1215511145 is 5411155121.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 805367641 + 410143504 = 28379^2 + 20252^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1215511145 - 2¹² = 1215507049 is a prime.

It is a super-2 number, since 2×1215511145² = 2954934687238422050, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19172 + ... + 52901.

It is an arithmetic number, because the mean of its divisors is an integer number (182383257).

Almost surely, 2^1215511145 is an apocalyptic number.

It is an amenable number.

1215511145 is a deficient number, since it is larger than the sum of its proper divisors (243554911).

1215511145 is an equidigital number, since it uses as much as digits as its factorization.

1215511145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75451.

The product of its digits is 1000, while the sum is 26.

The square root of 1215511145 is about 34864.1814044156. The cubic root of 1215511145 is about 1067.2176072593.

Adding to 1215511145 its reverse (5411155121), we get a palindrome (6626666266).

The spelling of 1215511145 in words is "one billion, two hundred fifteen million, five hundred eleven thousand, one hundred forty-five".