208641431 has 2 divisors, whose sum is σ = 208641432. Its totient is φ = 208641430.

The previous prime is 208641403. The next prime is 208641437. The reversal of 208641431 is 134146802.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-208641431 is a prime.

It is a super-2 number, since 2×208641431² = 87062493459455522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 208641394 and 208641403.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (208641437) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104320715 + 104320716.

It is an arithmetic number, because the mean of its divisors is an integer number (104320716).

Almost surely, 2^208641431 is an apocalyptic number.

208641431 is a deficient number, since it is larger than the sum of its proper divisors (1).

208641431 is an equidigital number, since it uses as much as digits as its factorization.

208641431 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4608, while the sum is 29.

The square root of 208641431 is about 14444.4256029792. The cubic root of 208641431 is about 593.1076389496.

The spelling of 208641431 in words is "two hundred eight million, six hundred forty-one thousand, four hundred thirty-one".