97881911917 has 4 divisors (see below), whose sum is σ = 97885930140. Its totient is φ = 97877893696.

The previous prime is 97881911879. The next prime is 97881911921. The reversal of 97881911917 is 71911918879.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 71911918879 = 877 ⋅81997627.

It can be written as a sum of positive squares in 2 ways, for example, as 69343215561 + 28538696356 = 263331^2 + 168934^2 .

It is a cyclic number.

It is not a de Polignac number, because 97881911917 - 2²⁷ = 97747694189 is a prime.

It is a super-2 number, since 2×97881911917² (a number of 23 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 (97881911717) 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, 1972348 + ... + 2021365.

It is an arithmetic number, because the mean of its divisors is an integer number (24471482535).

Almost surely, 2^97881911917 is an apocalyptic number.

It is an amenable number.

97881911917 is a deficient number, since it is larger than the sum of its proper divisors (4018223).

97881911917 is a wasteful number, since it uses less digits than its factorization.

97881911917 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4018222.

The product of its digits is 2286144, while the sum is 61.

The spelling of 97881911917 in words is "ninety-seven billion, eight hundred eighty-one million, nine hundred eleven thousand, nine hundred seventeen".