1601321318865 has 32 divisors (see below), whose sum is σ = 2938625510400. Its totient is φ = 826488420480.

The previous prime is 1601321318833. The next prime is 1601321318869. The reversal of 1601321318865 is 5688131231061.

1601321318865 is a `hidden beast` number, since 1 + 6 + 0 + 1 + 321 + 318 + 8 + 6 + 5 = 666.

It is not a de Polignac number, because 1601321318865 - 2⁵ = 1601321318833 is a prime.

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

It is a self number, because there is not a number n which added to its sum of digits gives 1601321318865.

It is not an unprimeable number, because it can be changed into a prime (1601321318869) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 191312580 + ... + 191320949.

It is an arithmetic number, because the mean of its divisors is an integer number (91832047200).

Almost surely, 2^{1601321318865} is an apocalyptic number.

1601321318865 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1601321318865 is a deficient number, since it is larger than the sum of its proper divisors (1337304191535).

1601321318865 is a wasteful number, since it uses less digits than its factorization.

1601321318865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 382633574 (or 382633568 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 45.

The spelling of 1601321318865 in words is "one trillion, six hundred one billion, three hundred twenty-one million, three hundred eighteen thousand, eight hundred sixty-five".