2145656155261 has 4 divisors (see below), whose sum is σ = 2182023208800. Its totient is φ = 2109289101724.

The previous prime is 2145656155243. The next prime is 2145656155283. The reversal of 2145656155261 is 1625516565412.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2145656155261 - 2²⁹ = 2145119284349 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2145656155241) 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, 18183526681 + ... + 18183526798.

It is an arithmetic number, because the mean of its divisors is an integer number (545505802200).

Almost surely, 2^{2145656155261} is an apocalyptic number.

It is an amenable number.

2145656155261 is a deficient number, since it is larger than the sum of its proper divisors (36367053539).

2145656155261 is an equidigital number, since it uses as much as digits as its factorization.

2145656155261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36367053538.

The product of its digits is 2160000, while the sum is 49.

The spelling of 2145656155261 in words is "two trillion, one hundred forty-five billion, six hundred fifty-six million, one hundred fifty-five thousand, two hundred sixty-one".