97978 has 4 divisors (see below), whose sum is σ = 146970. Its totient is φ = 48988.

The previous prime is 97973. The next prime is 97987. The reversal of 97978 is 87979.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 87979 = 97 ⋅907.

It can be written as a sum of positive squares in only one way, i.e., 97969 + 9 = 313^2 + 3^2 .

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an Ulam number.

It is a plaindrome in base 13.

It is a self number, because there is not a number n which added to its sum of digits gives 97978.

It is not an unprimeable number, because it can be changed into a prime (97973) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 24493 + ... + 24496.

2⁹⁷⁹⁷⁸ is an apocalyptic number.

97978 is a deficient number, since it is larger than the sum of its proper divisors (48992).

97978 is a wasteful number, since it uses less digits than its factorization.

97978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48991.

The product of its digits is 31752, while the sum is 40.

The square root of 97978 is about 313.0143766666. The cubic root of 97978 is about 46.1009126760.

Subtracting from 97978 its reverse (87979), we obtain a palindrome (9999).

The spelling of 97978 in words is "ninety-seven thousand, nine hundred seventy-eight".