997920268801 has 16 divisors (see below), whose sum is σ = 1026975611088. Its totient is φ = 969246720000.

The previous prime is 997920268789. The next prime is 997920268819. The reversal of 997920268801 is 108862029799.

It can be written as a sum of positive squares in 8 ways, for example, as 33892810000 + 964027458801 = 184100^2 + 981849^2 .

It is a 2-Lehmer number, since φ(997920268801) divides (997920268801-1)².

It is a cyclic number.

It is a Carmichael number.

It is not a de Polignac number, because 997920268801 - 2¹¹ = 997920266753 is a prime.

It is a deceptive number, since it divides R_997920268800.

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 997920268801.

It is not an unprimeable number, because it can be changed into a prime (997920268001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 51384445 + ... + 51403861.

It is an arithmetic number, because the mean of its divisors is an integer number (64185975693).

It is a Poulet number, since it divides 2^997920268800-1.

Almost surely, 2^997920268801 is an apocalyptic number.

It is an amenable number.

997920268801 is a deficient number, since it is larger than the sum of its proper divisors (29055342287).

997920268801 is a wasteful number, since it uses less digits than its factorization.

997920268801 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29172.

The product of its (nonzero) digits is 7838208, while the sum is 61.

The spelling of 997920268801 in words is "nine hundred ninety-seven billion, nine hundred twenty million, two hundred sixty-eight thousand, eight hundred one".