1215811025 has 72 divisors (see below), whose sum is σ = 1828632960. Its totient is φ = 796118400.

The previous prime is 1215811013. The next prime is 1215811067. The reversal of 1215811025 is 5201185121.

1215811025 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 1215811025 - 2⁸ = 1215810769 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1215810985 and 1215811003.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1690616 + ... + 1691334.

It is an arithmetic number, because the mean of its divisors is an integer number (25397680).

Almost surely, 2^1215811025 is an apocalyptic number.

It is an amenable number.

1215811025 is a deficient number, since it is larger than the sum of its proper divisors (612821935).

1215811025 is a wasteful number, since it uses less digits than its factorization.

1215811025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 807 (or 791 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 26.

The square root of 1215811025 is about 34868.4818281496. The cubic root of 1215811025 is about 1067.3053648259.

Adding to 1215811025 its reverse (5201185121), we get a palindrome (6416996146).

The spelling of 1215811025 in words is "one billion, two hundred fifteen million, eight hundred eleven thousand, twenty-five".