540623511621 has 20 divisors (see below), whose sum is σ = 807988668300. Its totient is φ = 360241364736.

The previous prime is 540623511569. The next prime is 540623511691. The reversal of 540623511621 is 126115326045.

540623511621 is a `hidden beast` number, since 5 + 4 + 0 + 6 + 23 + 5 + 1 + 1 + 621 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 48703634721 + 491919876900 = 220689^2 + 701370^2 .

It is not a de Polignac number, because 540623511621 - 2²⁷ = 540489293893 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (540623511691) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1445356 + ... + 1780533.

It is an arithmetic number, because the mean of its divisors is an integer number (40399433415).

Almost surely, 2^540623511621 is an apocalyptic number.

It is an amenable number.

540623511621 is a deficient number, since it is larger than the sum of its proper divisors (267365156679).

540623511621 is a wasteful number, since it uses less digits than its factorization.

540623511621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3227970 (or 3227961 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 36.

Adding to 540623511621 its reverse (126115326045), we get a palindrome (666738837666).

The spelling of 540623511621 in words is "five hundred forty billion, six hundred twenty-three million, five hundred eleven thousand, six hundred twenty-one".