40644344857 has 4 divisors (see below), whose sum is σ = 42045874020. Its totient is φ = 39242815696.

The previous prime is 40644344849. The next prime is 40644344863. The reversal of 40644344857 is 75844344604.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 30369684361 + 10274660496 = 174269^2 + 101364^2 .

It is a cyclic number.

It is not a de Polignac number, because 40644344857 - 2³ = 40644344849 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 40644344857.

It is not an unprimeable number, because it can be changed into a prime (40644344887) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 700764538 + ... + 700764595.

It is an arithmetic number, because the mean of its divisors is an integer number (10511468505).

Almost surely, 2^40644344857 is an apocalyptic number.

It is an amenable number.

40644344857 is a deficient number, since it is larger than the sum of its proper divisors (1401529163).

40644344857 is a wasteful number, since it uses less digits than its factorization.

40644344857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1401529162.

The product of its (nonzero) digits is 5160960, while the sum is 49.

The spelling of 40644344857 in words is "forty billion, six hundred forty-four million, three hundred forty-four thousand, eight hundred fifty-seven".