2115231212551 has 4 divisors (see below), whose sum is σ = 2183464477504. Its totient is φ = 2046997947600.

The previous prime is 2115231212527. The next prime is 2115231212581. The reversal of 2115231212551 is 1552121325112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2115231212551 - 2¹⁷ = 2115231081479 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31), and also a Moran number because the ratio is a prime number: 68233264921 = 2115231212551 / (2 + 1 + 1 + 5 + 2 + 3 + 1 + 2 + 1 + 2 + 5 + 5 + 1).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2115231212581) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 34116632430 + ... + 34116632491.

It is an arithmetic number, because the mean of its divisors is an integer number (545866119376).

Almost surely, 2^{2115231212551} is an apocalyptic number.

2115231212551 is a deficient number, since it is larger than the sum of its proper divisors (68233264953).

2115231212551 is an equidigital number, since it uses as much as digits as its factorization.

2115231212551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68233264952.

The product of its digits is 6000, while the sum is 31.

Adding to 2115231212551 its reverse (1552121325112), we get a palindrome (3667352537663).

The spelling of 2115231212551 in words is "two trillion, one hundred fifteen billion, two hundred thirty-one million, two hundred twelve thousand, five hundred fifty-one".