205979902 has 4 divisors (see below), whose sum is σ = 308969856. Its totient is φ = 102989950.

The previous prime is 205979867. The next prime is 205979923. The reversal of 205979902 is 209979502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 209979502 = 2 ⋅104989751.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 51494974 + ... + 51494977.

It is an arithmetic number, because the mean of its divisors is an integer number (77242464).

Almost surely, 2^205979902 is an apocalyptic number.

205979902 is a deficient number, since it is larger than the sum of its proper divisors (102989954).

205979902 is a wasteful number, since it uses less digits than its factorization.

205979902 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102989953.

The product of its (nonzero) digits is 102060, while the sum is 43.

The square root of 205979902 is about 14351.9999303233. Note that the first 4 decimals coincide. The cubic root of 205979902 is about 590.5748510074.

The spelling of 205979902 in words is "two hundred five million, nine hundred seventy-nine thousand, nine hundred two".