21539473194 has 16 divisors (see below), whose sum is σ = 43080959232. Its totient is φ = 7179488928.

The previous prime is 21539473181. The next prime is 21539473231. The reversal of 21539473194 is 49137493512.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 79822 + ... + 222374.

It is an arithmetic number, because the mean of its divisors is an integer number (2692559952).

Almost surely, 2^21539473194 is an apocalyptic number.

21539473194 is an abundant number, since it is smaller than the sum of its proper divisors (21541486038).

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

21539473194 is a wasteful number, since it uses less digits than its factorization.

21539473194 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167741.

The product of its digits is 816480, while the sum is 48.

The spelling of 21539473194 in words is "twenty-one billion, five hundred thirty-nine million, four hundred seventy-three thousand, one hundred ninety-four".