18344501820 has 72 divisors (see below), whose sum is σ = 55894640256. Its totient is φ = 4869919872.

The previous prime is 18344501809. The next prime is 18344501849. The reversal of 18344501820 is 2810544381.

18344501820 is a `hidden beast` number, since 183 + 4 + 450 + 1 + 8 + 20 = 666.

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 polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 188367 + ... + 268646.

It is an arithmetic number, because the mean of its divisors is an integer number (776314448).

Almost surely, 2^18344501820 is an apocalyptic number.

18344501820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18344501820 is an abundant number, since it is smaller than the sum of its proper divisors (37550138436).

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

18344501820 is a wasteful number, since it uses less digits than its factorization.

18344501820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 457251 (or 457246 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 36.

The spelling of 18344501820 in words is "eighteen billion, three hundred forty-four million, five hundred one thousand, eight hundred twenty".