18474221520 has 60 divisors (see below), whose sum is σ = 62042596356. Its totient is φ = 4926458880.

The previous prime is 18474221473. The next prime is 18474221533. The reversal of 18474221520 is 2512247481.

18474221520 is a `hidden beast` number, since 1 + 84 + 7 + 422 + 152 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 7216162704 + 11258058816 = 84948^2 + 106104^2 .

It is a tau number, because it is divible by the number of its divisors (60).

It is a super-2 number, since 2×18474221520² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12828601 + ... + 12830040.

Almost surely, 2^18474221520 is an apocalyptic number.

18474221520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18474221520 is an abundant number, since it is smaller than the sum of its proper divisors (43568374836).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18474221520 is a wasteful number, since it uses less digits than its factorization.

18474221520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25658660 (or 25658651 counting only the distinct ones).

The product of its (nonzero) digits is 35840, while the sum is 36.

The spelling of 18474221520 in words is "eighteen billion, four hundred seventy-four million, two hundred twenty-one thousand, five hundred twenty".