820645138194 has 16 divisors (see below), whose sum is σ = 1875760315968. Its totient is φ = 234470039472.

The previous prime is 820645138153. The next prime is 820645138253. The reversal of 820645138194 is 491831546028.

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, 9769584937 + ... + 9769585020.

It is an arithmetic number, because the mean of its divisors is an integer number (117235019748).

Almost surely, 2^820645138194 is an apocalyptic number.

820645138194 is an abundant number, since it is smaller than the sum of its proper divisors (1055115177774).

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

820645138194 is a wasteful number, since it uses less digits than its factorization.

820645138194 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19539169969.

The product of its (nonzero) digits is 1658880, while the sum is 51.

The spelling of 820645138194 in words is "eight hundred twenty billion, six hundred forty-five million, one hundred thirty-eight thousand, one hundred ninety-four".