40643531689 has 2 divisors, whose sum is σ = 40643531690. Its totient is φ = 40643531688.

The previous prime is 40643531629. The next prime is 40643531699. The reversal of 40643531689 is 98613534604.

It is a happy number.

40643531689 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 34016269225 + 6627262464 = 184435^2 + 81408^2 .

It is a cyclic number.

It is not a de Polignac number, because 40643531689 - 2¹³ = 40643523497 is a prime.

It is not a weakly prime, because it can be changed into another prime (40643531629) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20321765844 + 20321765845.

It is an arithmetic number, because the mean of its divisors is an integer number (20321765845).

Almost surely, 2^40643531689 is an apocalyptic number.

It is an amenable number.

40643531689 is a deficient number, since it is larger than the sum of its proper divisors (1).

40643531689 is an equidigital number, since it uses as much as digits as its factorization.

40643531689 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1866240, while the sum is 49.

The spelling of 40643531689 in words is "forty billion, six hundred forty-three million, five hundred thirty-one thousand, six hundred eighty-nine".