40643531817 has 36 divisors (see below), whose sum is σ = 65899063440. Its totient is φ = 22215055632.

The previous prime is 40643531777. The next prime is 40643531837. The reversal of 40643531817 is 71813534604.

It is a happy number.

It is not a de Polignac number, because 40643531817 - 2⁷ = 40643531689 is a prime.

It is not an unprimeable number, because it can be changed into a prime (40643531837) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 183567 + ... + 339092.

It is an arithmetic number, because the mean of its divisors is an integer number (1830529540).

Almost surely, 2^40643531817 is an apocalyptic number.

It is an amenable number.

40643531817 is a deficient number, since it is larger than the sum of its proper divisors (25255531623).

40643531817 is a wasteful number, since it uses less digits than its factorization.

40643531817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 522722 (or 522692 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 42.

The spelling of 40643531817 in words is "forty billion, six hundred forty-three million, five hundred thirty-one thousand, eight hundred seventeen".