18426520665 has 48 divisors (see below), whose sum is σ = 36515875968. Its totient is φ = 8420364288.

The previous prime is 18426520591. The next prime is 18426520667. The reversal of 18426520665 is 56602562481.

18426520665 is a `hidden beast` number, since 18 + 426 + 5 + 206 + 6 + 5 = 666.

It is not a de Polignac number, because 18426520665 - 2⁷ = 18426520537 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 18426520665.

It is not an unprimeable number, because it can be changed into a prime (18426520667) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 956569 + ... + 975641.

It is an arithmetic number, because the mean of its divisors is an integer number (760747416).

Almost surely, 2^18426520665 is an apocalyptic number.

18426520665 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18426520665 is a deficient number, since it is larger than the sum of its proper divisors (18089355303).

18426520665 is a wasteful number, since it uses less digits than its factorization.

18426520665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22158 (or 22155 counting only the distinct ones).

The product of its (nonzero) digits is 691200, while the sum is 45.

The spelling of 18426520665 in words is "eighteen billion, four hundred twenty-six million, five hundred twenty thousand, six hundred sixty-five".