18540544407 has 32 divisors (see below), whose sum is σ = 30990994944. Its totient is φ = 9578217600.

The previous prime is 18540544397. The next prime is 18540544409. The reversal of 18540544407 is 70444504581.

18540544407 = 17124² + 17125² + ... + 17186².

It is not a de Polignac number, because 18540544407 - 2⁴ = 18540544391 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18540544409) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 179908 + ... + 263529.

It is an arithmetic number, because the mean of its divisors is an integer number (968468592).

Almost surely, 2^18540544407 is an apocalyptic number.

18540544407 is a deficient number, since it is larger than the sum of its proper divisors (12450450537).

18540544407 is a wasteful number, since it uses less digits than its factorization.

18540544407 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 443639.

The product of its (nonzero) digits is 358400, while the sum is 42.

The spelling of 18540544407 in words is "eighteen billion, five hundred forty million, five hundred forty-four thousand, four hundred seven".