215478851839 has 4 divisors (see below), whose sum is σ = 215480034000. Its totient is φ = 215477669680.

The previous prime is 215478851831. The next prime is 215478851921. The reversal of 215478851839 is 938158874512.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 215478851839 - 2³ = 215478851831 is a prime.

It is a super-2 number, since 2×215478851839² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215478851831) 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, 253339 + ... + 703660.

It is an arithmetic number, because the mean of its divisors is an integer number (53870008500).

Almost surely, 2^215478851839 is an apocalyptic number.

215478851839 is a deficient number, since it is larger than the sum of its proper divisors (1182161).

215478851839 is an equidigital number, since it uses as much as digits as its factorization.

215478851839 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1182160.

The product of its digits is 19353600, while the sum is 61.

The spelling of 215478851839 in words is "two hundred fifteen billion, four hundred seventy-eight million, eight hundred fifty-one thousand, eight hundred thirty-nine".