2156641645 has 32 divisors (see below), whose sum is σ = 2763360000. Its totient is φ = 1611187200.

The previous prime is 2156641639. The next prime is 2156641649. The reversal of 2156641645 is 5461466512.

2156641645 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 2156641645 - 2⁷ = 2156641517 is a prime.

It is a super-3 number, since 3×2156641645³ (a number of 29 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a junction number, because it is equal to n+sod(n) for n = 2156641598 and 2156641607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2156641649) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2136901 + ... + 2137909.

It is an arithmetic number, because the mean of its divisors is an integer number (86355000).

Almost surely, 2^2156641645 is an apocalyptic number.

It is an amenable number.

2156641645 is a deficient number, since it is larger than the sum of its proper divisors (606718355).

2156641645 is a wasteful number, since it uses less digits than its factorization.

2156641645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1333.

The product of its digits is 172800, while the sum is 40.

The square root of 2156641645 is about 46439.6559526446. The cubic root of 2156641645 is about 1291.9905260946.

The spelling of 2156641645 in words is "two billion, one hundred fifty-six million, six hundred forty-one thousand, six hundred forty-five".