20121158815 has 4 divisors (see below), whose sum is σ = 24145390584. Its totient is φ = 16096927048.

The previous prime is 20121158797. The next prime is 20121158851. The reversal of 20121158815 is 51885112102.

It is a happy number.

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 20121158815 - 2⁹ = 20121158303 is a prime.

It is a super-2 number, since 2×20121158815² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2012115877 + ... + 2012115886.

It is an arithmetic number, because the mean of its divisors is an integer number (6036347646).

Almost surely, 2^20121158815 is an apocalyptic number.

20121158815 is a deficient number, since it is larger than the sum of its proper divisors (4024231769).

20121158815 is an equidigital number, since it uses as much as digits as its factorization.

20121158815 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4024231768.

The product of its (nonzero) digits is 6400, while the sum is 34.

The spelling of 20121158815 in words is "twenty billion, one hundred twenty-one million, one hundred fifty-eight thousand, eight hundred fifteen".