320991897661 has 8 divisors (see below), whose sum is σ = 340036977024. Its totient is φ = 301964952000.

The previous prime is 320991897643. The next prime is 320991897671. The reversal of 320991897661 is 166798199023.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 320991897661 - 2⁷ = 320991897533 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 320991897661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (320991897601) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4496965 + ... + 4567786.

It is an arithmetic number, because the mean of its divisors is an integer number (42504622128).

Almost surely, 2^320991897661 is an apocalyptic number.

It is an amenable number.

320991897661 is a deficient number, since it is larger than the sum of its proper divisors (19045079363).

320991897661 is a wasteful number, since it uses less digits than its factorization.

320991897661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9066851.

The product of its (nonzero) digits is 8817984, while the sum is 61.

The spelling of 320991897661 in words is "three hundred twenty billion, nine hundred ninety-one million, eight hundred ninety-seven thousand, six hundred sixty-one".