205987451 has 4 divisors (see below), whose sum is σ = 206130672. Its totient is φ = 205844232.

The previous prime is 205987447. The next prime is 205987459. The reversal of 205987451 is 154789502.

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

It is a cyclic number.

It is not a de Polignac number, because 205987451 - 2² = 205987447 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 205987399 and 205987408.

It is not an unprimeable number, because it can be changed into a prime (205987459) 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, 69431 + ... + 72336.

It is an arithmetic number, because the mean of its divisors is an integer number (51532668).

Almost surely, 2^205987451 is an apocalyptic number.

205987451 is a deficient number, since it is larger than the sum of its proper divisors (143221).

205987451 is a wasteful number, since it uses less digits than its factorization.

205987451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143220.

The product of its (nonzero) digits is 100800, while the sum is 41.

The square root of 205987451 is about 14352.2629226196. The cubic root of 205987451 is about 590.5820656192.

The spelling of 205987451 in words is "two hundred five million, nine hundred eighty-seven thousand, four hundred fifty-one".