2155869647 has 4 divisors (see below), whose sum is σ = 2158496376. Its totient is φ = 2153242920.

The previous prime is 2155869613. The next prime is 2155869659. The reversal of 2155869647 is 7469685512.

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 2155869647 - 2¹⁴ = 2155853263 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 (2155869607) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1312133 + ... + 1313774.

It is an arithmetic number, because the mean of its divisors is an integer number (539624094).

Almost surely, 2^2155869647 is an apocalyptic number.

2155869647 is a deficient number, since it is larger than the sum of its proper divisors (2626729).

2155869647 is an equidigital number, since it uses as much as digits as its factorization.

2155869647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2626728.

The product of its digits is 3628800, while the sum is 53.

The square root of 2155869647 is about 46431.3433684618. The cubic root of 2155869647 is about 1291.8363460773.

The spelling of 2155869647 in words is "two billion, one hundred fifty-five million, eight hundred sixty-nine thousand, six hundred forty-seven".