1971815968320 has 896 divisors, whose sum is σ = 7332990566400. Its totient is φ = 444203827200.

The previous prime is 1971815968313. The next prime is 1971815968321. The reversal of 1971815968320 is 238695181791.

It is a Harshad number since it is a multiple of its sum of digits (60).

It is not an unprimeable number, because it can be changed into a prime (1971815968321) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 2173997307 + ... + 2173998213.

Almost surely, 2^{1971815968320} is an apocalyptic number.

1971815968320 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 1971815968320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3666495283200).

1971815968320 is an abundant number, since it is smaller than the sum of its proper divisors (5361174598080).

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

1971815968320 is a wasteful number, since it uses less digits than its factorization.

1971815968320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1227 (or 1217 counting only the distinct ones).

The product of its (nonzero) digits is 6531840, while the sum is 60.

The spelling of 1971815968320 in words is "one trillion, nine hundred seventy-one billion, eight hundred fifteen million, nine hundred sixty-eight thousand, three hundred twenty".