2158639439 has 4 divisors (see below), whose sum is σ = 2354879400. Its totient is φ = 1962399480.

The previous prime is 2158639421. The next prime is 2158639487. The reversal of 2158639439 is 9349368512.

It is a happy number.

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 2158639439 - 2¹⁶ = 2158573903 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 (2158639409) 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, 98119964 + ... + 98119985.

It is an arithmetic number, because the mean of its divisors is an integer number (588719850).

Almost surely, 2^2158639439 is an apocalyptic number.

2158639439 is a deficient number, since it is larger than the sum of its proper divisors (196239961).

2158639439 is a wasteful number, since it uses less digits than its factorization.

2158639439 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 196239960.

The product of its digits is 1399680, while the sum is 50.

The square root of 2158639439 is about 46461.1605429740. The cubic root of 2158639439 is about 1292.3893459188.

The spelling of 2158639439 in words is "two billion, one hundred fifty-eight million, six hundred thirty-nine thousand, four hundred thirty-nine".