997375675591 has 4 divisors (see below), whose sum is σ = 997378077784. Its totient is φ = 997373273400.

The previous prime is 997375675577. The next prime is 997375675601. The reversal of 997375675591 is 195576573799.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 195576573799 = 121963 ⋅1603573.

It is a 3-Lehmer number, since φ(997375675591) divides (997375675591-1)³.

It is a cyclic number.

It is not a de Polignac number, because 997375675591 - 2¹³ = 997375667399 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (997375675501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 400365 + ... + 1468006.

It is an arithmetic number, because the mean of its divisors is an integer number (249344519446).

Almost surely, 2^997375675591 is an apocalyptic number.

997375675591 is the 533821-st nonagonal number.

997375675591 is a deficient number, since it is larger than the sum of its proper divisors (2402193).

997375675591 is a wasteful number, since it uses less digits than its factorization.

997375675591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2402192.

The product of its digits is 562605750, while the sum is 73.

The spelling of 997375675591 in words is "nine hundred ninety-seven billion, three hundred seventy-five million, six hundred seventy-five thousand, five hundred ninety-one".