2148678391 has 4 divisors (see below), whose sum is σ = 2148838984. Its totient is φ = 2148517800.

The previous prime is 2148678379. The next prime is 2148678397. The reversal of 2148678391 is 1938768412.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2148678391 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 (2148678397) 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, 58200 + ... + 87661.

It is an arithmetic number, because the mean of its divisors is an integer number (537209746).

Almost surely, 2^2148678391 is an apocalyptic number.

2148678391 is a deficient number, since it is larger than the sum of its proper divisors (160593).

2148678391 is a wasteful number, since it uses less digits than its factorization.

2148678391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160592.

The product of its digits is 580608, while the sum is 49.

The square root of 2148678391 is about 46353.8390103776. The cubic root of 2148678391 is about 1290.3983688433.

The spelling of 2148678391 in words is "two billion, one hundred forty-eight million, six hundred seventy-eight thousand, three hundred ninety-one".