43685431 has 2 divisors, whose sum is σ = 43685432. Its totient is φ = 43685430.

The previous prime is 43685423. The next prime is 43685437. The reversal of 43685431 is 13458634.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 43685431 - 2³ = 43685423 is a prime.

It is a super-2 number, since 2×43685431² = 3816833763311522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (43685437) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21842715 + 21842716.

It is an arithmetic number, because the mean of its divisors is an integer number (21842716).

Almost surely, 2^43685431 is an apocalyptic number.

43685431 is a deficient number, since it is larger than the sum of its proper divisors (1).

43685431 is an equidigital number, since it uses as much as digits as its factorization.

43685431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34560, while the sum is 34.

The square root of 43685431 is about 6609.4955178137. The cubic root of 43685431 is about 352.1915038135.

The spelling of 43685431 in words is "forty-three million, six hundred eighty-five thousand, four hundred thirty-one".