1320645338999 has 16 divisors (see below), whose sum is σ = 1591321324800. Its totient is φ = 1070665573824.

The previous prime is 1320645338989. The next prime is 1320645339001. The reversal of 1320645338999 is 9998335460231.

It is not a de Polignac number, because 1320645338999 - 2⁴ = 1320645338983 is a prime.

It is a super-2 number, since 2×1320645338999² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1320645338989) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7964669 + ... + 8128790.

It is an arithmetic number, because the mean of its divisors is an integer number (99457582800).

Almost surely, 2^{1320645338999} is an apocalyptic number.

1320645338999 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

1320645338999 is a deficient number, since it is larger than the sum of its proper divisors (270675985801).

1320645338999 is a wasteful number, since it uses less digits than its factorization.

1320645338999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16094102.

The product of its (nonzero) digits is 37791360, while the sum is 62.

The spelling of 1320645338999 in words is "one trillion, three hundred twenty billion, six hundred forty-five million, three hundred thirty-eight thousand, nine hundred ninety-nine".