97866989021 has 4 divisors (see below), whose sum is σ = 103017883200. Its totient is φ = 92716094844.

The previous prime is 97866988997. The next prime is 97866989081. The reversal of 97866989021 is 12098966879.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12098966879 = 20359 ⋅594281.

It is a cyclic number.

It is not a de Polignac number, because 97866989021 - 2¹⁰ = 97866987997 is a prime.

It is a super-5 number, since 5×97866989021⁵ (a number of 56 digits) contains 55555 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (97866989081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2575447061 + ... + 2575447098.

It is an arithmetic number, because the mean of its divisors is an integer number (25754470800).

Almost surely, 2^97866989021 is an apocalyptic number.

It is an amenable number.

97866989021 is a deficient number, since it is larger than the sum of its proper divisors (5150894179).

97866989021 is a wasteful number, since it uses less digits than its factorization.

97866989021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5150894178.

The product of its (nonzero) digits is 23514624, while the sum is 65.

The spelling of 97866989021 in words is "ninety-seven billion, eight hundred sixty-six million, nine hundred eighty-nine thousand, twenty-one".