1215463861 has 4 divisors (see below), whose sum is σ = 1215576832. Its totient is φ = 1215350892.

The previous prime is 1215463849. The next prime is 1215463867. The reversal of 1215463861 is 1683645121.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1215463861 - 2⁵ = 1215463829 is a prime.

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 1215463861.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1215463867) 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 in 3 ways as a sum of consecutive naturals, for example, 38421 + ... + 62506.

It is an arithmetic number, because the mean of its divisors is an integer number (303894208).

Almost surely, 2^1215463861 is an apocalyptic number.

It is an amenable number.

1215463861 is a deficient number, since it is larger than the sum of its proper divisors (112971).

1215463861 is a wasteful number, since it uses less digits than its factorization.

1215463861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112970.

The product of its digits is 34560, while the sum is 37.

The square root of 1215463861 is about 34863.5032806515. The cubic root of 1215463861 is about 1067.2037686444.

The spelling of 1215463861 in words is "one billion, two hundred fifteen million, four hundred sixty-three thousand, eight hundred sixty-one".