205121007 has 72 divisors (see below), whose sum is σ = 381597216. Its totient is φ = 105162624.

The previous prime is 205121003. The next prime is 205121009. The reversal of 205121007 is 700121502.

It is not a de Polignac number, because 205121007 - 2² = 205121003 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205121003) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 211638 + ... + 212604.

Almost surely, 2^205121007 is an apocalyptic number.

205121007 is a deficient number, since it is larger than the sum of its proper divisors (176476209).

205121007 is a wasteful number, since it uses less digits than its factorization.

205121007 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1037 (or 1027 counting only the distinct ones).

The product of its (nonzero) digits is 140, while the sum is 18.

The square root of 205121007 is about 14322.0461876088. The cubic root of 205121007 is about 589.7528477411.

Adding to 205121007 its reverse (700121502), we get a palindrome (905242509).

The spelling of 205121007 in words is "two hundred five million, one hundred twenty-one thousand, seven".