205121642 has 16 divisors (see below), whose sum is σ = 341344800. Its totient is φ = 91656240.

The previous prime is 205121641. The next prime is 205121681. The reversal of 205121642 is 246121502.

It is a happy number.

205121642 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (205121641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 77717 + ... + 80312.

It is an arithmetic number, because the mean of its divisors is an integer number (21334050).

Almost surely, 2^205121642 is an apocalyptic number.

205121642 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

205121642 is a deficient number, since it is larger than the sum of its proper divisors (136223158).

205121642 is a wasteful number, since it uses less digits than its factorization.

205121642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 158101.

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 205121642 is about 14322.0683562117. The cubic root of 205121642 is about 589.7534563130.

The spelling of 205121642 in words is "two hundred five million, one hundred twenty-one thousand, six hundred forty-two".