205672991 has 2 divisors, whose sum is σ = 205672992. Its totient is φ = 205672990.

The previous prime is 205672963. The next prime is 205672993. The reversal of 205672991 is 199276502.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 205672991 - 2⁶ = 205672927 is a prime.

Together with 205672993, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (205672993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102836495 + 102836496.

It is an arithmetic number, because the mean of its divisors is an integer number (102836496).

Almost surely, 2^205672991 is an apocalyptic number.

205672991 is a deficient number, since it is larger than the sum of its proper divisors (1).

205672991 is an equidigital number, since it uses as much as digits as its factorization.

205672991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 68040, while the sum is 41.

The square root of 205672991 is about 14341.3036715635. The cubic root of 205672991 is about 590.2813854573.

The spelling of 205672991 in words is "two hundred five million, six hundred seventy-two thousand, nine hundred ninety-one".