40681561 has 8 divisors (see below), whose sum is σ = 43216200. Its totient is φ = 38162688.

The previous prime is 40681559. The next prime is 40681573. The reversal of 40681561 is 16518604.

It can be written as a sum of positive squares in 4 ways, for example, as 7733961 + 32947600 = 2781^2 + 5740^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 40681561 - 2¹ = 40681559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (40681591) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1615 + ... + 9163.

It is an arithmetic number, because the mean of its divisors is an integer number (5402025).

Almost surely, 2^40681561 is an apocalyptic number.

It is an amenable number.

40681561 is a deficient number, since it is larger than the sum of its proper divisors (2534639).

40681561 is a wasteful number, since it uses less digits than its factorization.

40681561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7883.

The product of its (nonzero) digits is 5760, while the sum is 31.

The square root of 40681561 is about 6378.2098585732. The cubic root of 40681561 is about 343.9266818010.

The spelling of 40681561 in words is "forty million, six hundred eighty-one thousand, five hundred sixty-one".