1913321620728 has 96 divisors (see below), whose sum is σ = 5927615890560. Its totient is φ = 546162096960.

The previous prime is 1913321620709. The next prime is 1913321620729. The reversal of 1913321620728 is 8270261233191.

It is a happy number.

1913321620728 is a `hidden beast` number, since 1 + 9 + 13 + 3 + 2 + 1 + 620 + 7 + 2 + 8 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1913321620729) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1189950 + ... + 2289677.

It is an arithmetic number, because the mean of its divisors is an integer number (61745998860).

Almost surely, 2^{1913321620728} is an apocalyptic number.

1913321620728 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

1913321620728 is an abundant number, since it is smaller than the sum of its proper divisors (4014294269832).

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

1913321620728 is a wasteful number, since it uses less digits than its factorization.

1913321620728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3480737 (or 3480730 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The spelling of 1913321620728 in words is "one trillion, nine hundred thirteen billion, three hundred twenty-one million, six hundred twenty thousand, seven hundred twenty-eight".