2156205211045 has 4 divisors (see below), whose sum is σ = 2587446253260. Its totient is φ = 1724964168832.

The previous prime is 2156205211031. The next prime is 2156205211117. The reversal of 2156205211045 is 5401125026512.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1663826531236 + 492378679809 = 1289894^2 + 701697^2 .

It is a cyclic number.

It is not a de Polignac number, because 2156205211045 - 2²⁷ = 2156070993317 is a prime.

It is a super-2 number, since 2×2156205211045² (a number of 25 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 2156205211045.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 215620521100 + ... + 215620521109.

It is an arithmetic number, because the mean of its divisors is an integer number (646861563315).

Almost surely, 2^{2156205211045} is an apocalyptic number.

It is an amenable number.

2156205211045 is a deficient number, since it is larger than the sum of its proper divisors (431241042215).

2156205211045 is an equidigital number, since it uses as much as digits as its factorization.

2156205211045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 431241042214.

The product of its (nonzero) digits is 24000, while the sum is 34.

The spelling of 2156205211045 in words is "two trillion, one hundred fifty-six billion, two hundred five million, two hundred eleven thousand, forty-five".