215891029478 has 8 divisors (see below), whose sum is σ = 340880572920. Its totient is φ = 102264171840.

The previous prime is 215891029451. The next prime is 215891029489. The reversal of 215891029478 is 874920198512.

215891029478 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2840671403 + ... + 2840671478.

It is an arithmetic number, because the mean of its divisors is an integer number (42610071615).

Almost surely, 2^215891029478 is an apocalyptic number.

215891029478 is a deficient number, since it is larger than the sum of its proper divisors (124989543442).

215891029478 is a wasteful number, since it uses less digits than its factorization.

215891029478 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5681342902.

The product of its (nonzero) digits is 2903040, while the sum is 56.

The spelling of 215891029478 in words is "two hundred fifteen billion, eight hundred ninety-one million, twenty-nine thousand, four hundred seventy-eight".