18236409520 has 40 divisors (see below), whose sum is σ = 48456746784. Its totient is φ = 6252483072.

The previous prime is 18236409497. The next prime is 18236409553. The reversal of 18236409520 is 2590463281.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×18236409520² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16281949 + ... + 16283068.

Almost surely, 2^18236409520 is an apocalyptic number.

18236409520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18236409520 is an abundant number, since it is smaller than the sum of its proper divisors (30220337264).

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

18236409520 is a wasteful number, since it uses less digits than its factorization.

18236409520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32565037 (or 32565031 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 40.

The spelling of 18236409520 in words is "eighteen billion, two hundred thirty-six million, four hundred nine thousand, five hundred twenty".