205436251001 has 4 divisors (see below), whose sum is σ = 217520736372. Its totient is φ = 193351765632.

The previous prime is 205436250989. The next prime is 205436251049. The reversal of 205436251001 is 100152634502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 100152634502 = 2 ⋅50076317251.

It can be written as a sum of positive squares in 2 ways, for example, as 69145332025 + 136290918976 = 262955^2 + 369176^2 .

It is a cyclic number.

It is not a de Polignac number, because 205436251001 - 2²⁶ = 205369142137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205436251061) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6042242660 + ... + 6042242693.

It is an arithmetic number, because the mean of its divisors is an integer number (54380184093).

Almost surely, 2^205436251001 is an apocalyptic number.

It is an amenable number.

205436251001 is a deficient number, since it is larger than the sum of its proper divisors (12084485371).

205436251001 is a wasteful number, since it uses less digits than its factorization.

205436251001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12084485370.

The product of its (nonzero) digits is 7200, while the sum is 29.

Adding to 205436251001 its reverse (100152634502), we get a palindrome (305588885503).

The spelling of 205436251001 in words is "two hundred five billion, four hundred thirty-six million, two hundred fifty-one thousand, one".