1215412115551 has 16 divisors (see below), whose sum is σ = 1246440835584. Its totient is φ = 1184685825024.

The previous prime is 1215412115543. The next prime is 1215412115557. The reversal of 1215412115551 is 1555112145121.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 1215412115551 - 2³ = 1215412115543 is a prime.

It is a super-2 number, since 2×1215412115551² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1215412115557) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 85724175 + ... + 85738351.

It is an arithmetic number, because the mean of its divisors is an integer number (77902552224).

Almost surely, 2^{1215412115551} is an apocalyptic number.

1215412115551 is a deficient number, since it is larger than the sum of its proper divisors (31028720033).

1215412115551 is a wasteful number, since it uses less digits than its factorization.

1215412115551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24690.

The product of its digits is 10000, while the sum is 34.

The spelling of 1215412115551 in words is "one trillion, two hundred fifteen billion, four hundred twelve million, one hundred fifteen thousand, five hundred fifty-one".