1321543641600 has 4320 divisors, whose sum is σ = 6632451745920. Its totient is φ = 257511260160.

The previous prime is 1321543641511. The next prime is 1321543641601. The reversal of 1321543641600 is 61463451231.

1321543641600 is a `hidden beast` number, since 1 + 3 + 2 + 1 + 5 + 4 + 3 + 6 + 41 + 600 = 666.

It is a tau number, because it is divible by the number of its divisors (4320).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321543641601) by changing a digit.

It is a polite number, since it can be written in 431 ways as a sum of consecutive naturals, for example, 45570470386 + ... + 45570470414.

It is an arithmetic number, because the mean of its divisors is an integer number (1535289756).

Almost surely, 2^{1321543641600} is an apocalyptic number.

1321543641600 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 1321543641600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3316225872960).

1321543641600 is an abundant number, since it is smaller than the sum of its proper divisors (5310908104320).

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

1321543641600 is a wasteful number, since it uses less digits than its factorization.

1321543641600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122 (or 82 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The spelling of 1321543641600 in words is "one trillion, three hundred twenty-one billion, five hundred forty-three million, six hundred forty-one thousand, six hundred".