40440465561 has 4 divisors (see below), whose sum is σ = 53920620752. Its totient is φ = 26960310372.

The previous prime is 40440465551. The next prime is 40440465587. The reversal of 40440465561 is 16556404404.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 40440465561 - 2¹⁵ = 40440432793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (40440465551) 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, 6740077591 + ... + 6740077596.

It is an arithmetic number, because the mean of its divisors is an integer number (13480155188).

Almost surely, 2^40440465561 is an apocalyptic number.

It is an amenable number.

40440465561 is a deficient number, since it is larger than the sum of its proper divisors (13480155191).

40440465561 is a wasteful number, since it uses less digits than its factorization.

40440465561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13480155190.

The product of its (nonzero) digits is 230400, while the sum is 39.

Adding to 40440465561 its reverse (16556404404), we get a palindrome (56996869965).

It can be divided in two parts, 404404 and 65561, that added together give a triangular number (469965 = T₉₆₉).

The spelling of 40440465561 in words is "forty billion, four hundred forty million, four hundred sixty-five thousand, five hundred sixty-one".