97815994871 has 4 divisors (see below), whose sum is σ = 111789708432. Its totient is φ = 83842281312.

The previous prime is 97815994699. The next prime is 97815994879. The reversal of 97815994871 is 17849951879.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 17849951879 = 63587 ⋅280717.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-97815994871 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 (97815994879) 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, 6986856770 + ... + 6986856783.

It is an arithmetic number, because the mean of its divisors is an integer number (27947427108).

Almost surely, 2^97815994871 is an apocalyptic number.

97815994871 is a deficient number, since it is larger than the sum of its proper divisors (13973713561).

97815994871 is a wasteful number, since it uses less digits than its factorization.

97815994871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13973713560.

The product of its digits is 45722880, while the sum is 68.

The spelling of 97815994871 in words is "ninety-seven billion, eight hundred fifteen million, nine hundred ninety-four thousand, eight hundred seventy-one".