206405431 has 2 divisors, whose sum is σ = 206405432. Its totient is φ = 206405430.

The previous prime is 206405401. The next prime is 206405443. The reversal of 206405431 is 134504602.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 206405431 - 2¹¹ = 206403383 is a prime.

It is a super-2 number, since 2×206405431² = 85206403892591522, which contains 22 as substring.

It is equal to p_11413834 and since 206405431 and 11413834 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 206405396 and 206405405.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (206405401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103202715 + 103202716.

It is an arithmetic number, because the mean of its divisors is an integer number (103202716).

Almost surely, 2^206405431 is an apocalyptic number.

206405431 is a deficient number, since it is larger than the sum of its proper divisors (1).

206405431 is an equidigital number, since it uses as much as digits as its factorization.

206405431 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2880, while the sum is 25.

The square root of 206405431 is about 14366.8170100409. The cubic root of 206405431 is about 590.9812561396.

The spelling of 206405431 in words is "two hundred six million, four hundred five thousand, four hundred thirty-one".