18361969920 has 576 divisors, whose sum is σ = 76036800000. Its totient is φ = 4194312192.

The previous prime is 18361969907. The next prime is 18361969931. The reversal of 18361969920 is 2996916381.

18361969920 is a `hidden beast` number, since 18 + 3 + 619 + 6 + 9 + 9 + 2 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (576).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 11853306 + ... + 11854854.

Almost surely, 2^18361969920 is an apocalyptic number.

18361969920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18361969920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38018400000).

18361969920 is an abundant number, since it is smaller than the sum of its proper divisors (57674830080).

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

18361969920 is an equidigital number, since it uses as much as digits as its factorization.

18361969920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1600 (or 1566 counting only the distinct ones).

The product of its (nonzero) digits is 1259712, while the sum is 54.

The spelling of 18361969920 in words is "eighteen billion, three hundred sixty-one million, nine hundred sixty-nine thousand, nine hundred twenty".