18971971200 has 1536 divisors, whose sum is σ = 90660864000. Its totient is φ = 3762339840.

The previous prime is 18971971189. The next prime is 18971971211. The reversal of 18971971200 is 217917981.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (18971971189) and next prime (18971971211).

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

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 149385537 + ... + 149385663.

It is an arithmetic number, because the mean of its divisors is an integer number (59024000).

Almost surely, 2^18971971200 is an apocalyptic number.

18971971200 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 18971971200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45330432000).

18971971200 is an abundant number, since it is smaller than the sum of its proper divisors (71688892800).

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

18971971200 is a wasteful number, since it uses less digits than its factorization.

18971971200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199 (or 176 counting only the distinct ones).

The product of its (nonzero) digits is 63504, while the sum is 45.

The spelling of 18971971200 in words is "eighteen billion, nine hundred seventy-one million, nine hundred seventy-one thousand, two hundred".