1215551555125 has 8 divisors (see below), whose sum is σ = 1517008340952. Its totient is φ = 972441244000.

The previous prime is 1215551555111. The next prime is 1215551555161. The reversal of 1215551555125 is 5215551555121.

It can be written as a sum of positive squares in 4 ways, for example, as 24183671121 + 1191367884004 = 155511^2 + 1091498^2 .

It is not a de Polignac number, because 1215551555125 - 2⁵ = 1215551555093 is a prime.

It is a hoax number, since the sum of its digits (43) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a congruent 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, 4862206096 + ... + 4862206345.

It is an arithmetic number, because the mean of its divisors is an integer number (189626042619).

Almost surely, 2^{1215551555125} is an apocalyptic number.

It is an amenable number.

1215551555125 is a deficient number, since it is larger than the sum of its proper divisors (301456785827).

1215551555125 is an frugal number, since it uses more digits than its factorization.

1215551555125 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9724412456 (or 9724412446 counting only the distinct ones).

The product of its digits is 312500, while the sum is 43.

The spelling of 1215551555125 in words is "one trillion, two hundred fifteen billion, five hundred fifty-one million, five hundred fifty-five thousand, one hundred twenty-five".