40126561 has 4 divisors (see below), whose sum is σ = 40299012. Its totient is φ = 39954112.

The previous prime is 40126553. The next prime is 40126571. The reversal of 40126561 is 16562104.

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 3825936 + 36300625 = 1956^2 + 6025^2 .

It is a cyclic number.

It is not a de Polignac number, because 40126561 - 2³ = 40126553 is a prime.

It is a super-2 number, since 2×40126561² = 3220281795373442, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (40126571) 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, 85876 + ... + 86341.

It is an arithmetic number, because the mean of its divisors is an integer number (10074753).

Almost surely, 2^40126561 is an apocalyptic number.

It is an amenable number.

40126561 is a deficient number, since it is larger than the sum of its proper divisors (172451).

40126561 is a wasteful number, since it uses less digits than its factorization.

40126561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 172450.

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 40126561 is about 6334.5529439732. The cubic root of 40126561 is about 342.3555033642.

Adding to 40126561 its reverse (16562104), we get a palindrome (56688665).

It can be divided in two parts, 401 and 26561, that added together give a palindrome (26962).

The spelling of 40126561 in words is "forty million, one hundred twenty-six thousand, five hundred sixty-one".