2154217879 has 4 divisors (see below), whose sum is σ = 2350055880. Its totient is φ = 1958379880.

The previous prime is 2154217873. The next prime is 2154217889. The reversal of 2154217879 is 9787124512.

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 2154217879 - 2¹¹ = 2154215831 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 (2154217873) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 97918984 + ... + 97919005.

It is an arithmetic number, because the mean of its divisors is an integer number (587513970).

Almost surely, 2^2154217879 is an apocalyptic number.

2154217879 is a deficient number, since it is larger than the sum of its proper divisors (195838001).

2154217879 is a wasteful number, since it uses less digits than its factorization.

2154217879 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 195838000.

The product of its digits is 282240, while the sum is 46.

The square root of 2154217879 is about 46413.5527513247. The cubic root of 2154217879 is about 1291.5063386285.

The spelling of 2154217879 in words is "two billion, one hundred fifty-four million, two hundred seventeen thousand, eight hundred seventy-nine".