97128778 has 4 divisors (see below), whose sum is σ = 145693170. Its totient is φ = 48564388.

The previous prime is 97128767. The next prime is 97128791. The reversal of 97128778 is 87782179.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 87782179 = 8663 ⋅10133.

It can be written as a sum of positive squares in only one way, i.e., 95394289 + 1734489 = 9767^2 + 1317^2 .

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 24282193 + ... + 24282196.

Almost surely, 2^97128778 is an apocalyptic number.

97128778 is a deficient number, since it is larger than the sum of its proper divisors (48564392).

97128778 is a wasteful number, since it uses less digits than its factorization.

97128778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48564391.

The product of its digits is 395136, while the sum is 49.

The square root of 97128778 is about 9855.3933457777. The cubic root of 97128778 is about 459.6733313985.

The spelling of 97128778 in words is "ninety-seven million, one hundred twenty-eight thousand, seven hundred seventy-eight".