1901666321280 has 768 divisors, whose sum is σ = 7784099481600. Its totient is φ = 422649446400.

The previous prime is 1901666321239. The next prime is 1901666321281. The reversal of 1901666321280 is 821236661091.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1901666321281) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 37293562 + ... + 37344518.

It is an arithmetic number, because the mean of its divisors is an integer number (10135546200).

Almost surely, 2^{1901666321280} is an apocalyptic number.

1901666321280 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 1901666321280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3892049740800).

1901666321280 is an abundant number, since it is smaller than the sum of its proper divisors (5882433160320).

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

1901666321280 is a wasteful number, since it uses less digits than its factorization.

1901666321280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51043 (or 51028 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 45.

The spelling of 1901666321280 in words is "one trillion, nine hundred one billion, six hundred sixty-six million, three hundred twenty-one thousand, two hundred eighty".