40540821128581 has 4 divisors (see below), whose sum is σ = 40958767738252. Its totient is φ = 40122874518912.

The previous prime is 40540821128503. The next prime is 40540821128597. The reversal of 40540821128581 is 18582112804504.

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 12715892424225 + 27824928704356 = 3565935^2 + 5274934^2 .

It is a cyclic number.

It is not a de Polignac number, because 40540821128581 - 2¹⁵ = 40540821095813 is a prime.

It is a super-2 number, since 2×40540821128581² (a number of 28 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40540821126581) 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, 208973304690 + ... + 208973304883.

It is an arithmetic number, because the mean of its divisors is an integer number (10239691934563).

Almost surely, 2^{40540821128581} is an apocalyptic number.

It is an amenable number.

40540821128581 is a deficient number, since it is larger than the sum of its proper divisors (417946609671).

40540821128581 is an equidigital number, since it uses as much as digits as its factorization.

40540821128581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 417946609670.

The product of its (nonzero) digits is 819200, while the sum is 49.

The spelling of 40540821128581 in words is "forty trillion, five hundred forty billion, eight hundred twenty-one million, one hundred twenty-eight thousand, five hundred eighty-one".