1215877991628 has 18 divisors (see below), whose sum is σ = 2837057559924. Its totient is φ = 405291390624.

The previous prime is 1215877991591. The next prime is 1215877991639. The reversal of 1215877991628 is 8261997785121.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3660600 + ... + 3978912.

Almost surely, 2^{1215877991628} is an apocalyptic number.

It is an amenable number.

1215877991628 is an abundant number, since it is smaller than the sum of its proper divisors (1621179568296).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1215877991628 is an frugal number, since it uses more digits than its factorization.

1215877991628 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 636633 (or 318318 counting only the distinct ones).

The product of its digits is 30481920, while the sum is 66.

The spelling of 1215877991628 in words is "one trillion, two hundred fifteen billion, eight hundred seventy-seven million, nine hundred ninety-one thousand, six hundred twenty-eight".