1781901313920 has 3072 divisors, whose sum is σ = 8503129958400. Its totient is φ = 343125393408.

The previous prime is 1781901313891. The next prime is 1781901313991. The reversal of 1781901313920 is 293131091871.

It is a happy number.

1781901313920 is a `hidden beast` number, since 1 + 78 + 190 + 1 + 3 + 1 + 392 + 0 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 24409607004 + ... + 24409607076.

It is an arithmetic number, because the mean of its divisors is an integer number (2767945950).

Almost surely, 2^{1781901313920} is an apocalyptic number.

1781901313920 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 1781901313920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4251564979200).

1781901313920 is an abundant number, since it is smaller than the sum of its proper divisors (6721228644480).

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

1781901313920 is a wasteful number, since it uses less digits than its factorization.

1781901313920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 202 (or 165 counting only the distinct ones).

The product of its (nonzero) digits is 81648, while the sum is 45.

The spelling of 1781901313920 in words is "one trillion, seven hundred eighty-one billion, nine hundred one million, three hundred thirteen thousand, nine hundred twenty".