2156121543121 has 8 divisors (see below), whose sum is σ = 2653688053184. Its totient is φ = 1705942319760.

The previous prime is 2156121543113. The next prime is 2156121543127. The reversal of 2156121543121 is 1213451216512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 2156121543121 - 2³ = 2156121543113 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2156121543127) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11846821575 + ... + 11846821756.

It is an arithmetic number, because the mean of its divisors is an integer number (331711006648).

Almost surely, 2^{2156121543121} is an apocalyptic number.

It is an amenable number.

2156121543121 is a deficient number, since it is larger than the sum of its proper divisors (497566510063).

2156121543121 is a wasteful number, since it uses less digits than its factorization.

2156121543121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23693643351.

The product of its digits is 14400, while the sum is 34.

Adding to 2156121543121 its reverse (1213451216512), we get a palindrome (3369572759633).

The spelling of 2156121543121 in words is "two trillion, one hundred fifty-six billion, one hundred twenty-one million, five hundred forty-three thousand, one hundred twenty-one".