215478851838 has 32 divisors (see below), whose sum is σ = 453688560000. Its totient is φ = 68038622496.

The previous prime is 215478851831. The next prime is 215478851921. The reversal of 215478851838 is 838158874512.

It is a happy number.

215478851838 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×215478851838² (a number of 23 digits) contains 22 as substring.

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 15 ways as a sum of consecutive naturals, for example, 1014445 + ... + 1208327.

It is an arithmetic number, because the mean of its divisors is an integer number (14177767500).

Almost surely, 2^215478851838 is an apocalyptic number.

215478851838 is an abundant number, since it is smaller than the sum of its proper divisors (238209708162).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

215478851838 is a wasteful number, since it uses less digits than its factorization.

215478851838 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 203656.

The product of its digits is 17203200, while the sum is 60.

The spelling of 215478851838 in words is "two hundred fifteen billion, four hundred seventy-eight million, eight hundred fifty-one thousand, eight hundred thirty-eight".