205054638406 has 4 divisors (see below), whose sum is σ = 307581957612. Its totient is φ = 102527319202.

The previous prime is 205054638337. The next prime is 205054638407. The reversal of 205054638406 is 604836450502.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205054638407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 51263659600 + ... + 51263659603.

It is an arithmetic number, because the mean of its divisors is an integer number (76895489403).

Almost surely, 2^205054638406 is an apocalyptic number.

205054638406 is a deficient number, since it is larger than the sum of its proper divisors (102527319206).

205054638406 is a wasteful number, since it uses less digits than its factorization.

205054638406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102527319205.

The product of its (nonzero) digits is 691200, while the sum is 43.

The spelling of 205054638406 in words is "two hundred five billion, fifty-four million, six hundred thirty-eight thousand, four hundred six".