97128779 has 16 divisors (see below), whose sum is σ = 112320000. Its totient is φ = 83063520.

The previous prime is 97128767. The next prime is 97128791. The reversal of 97128779 is 97782179.

It is an interprime number because it is at equal distance from previous prime (97128767) and next prime (97128791).

It is a cyclic number.

It is not a de Polignac number, because 97128779 - 2⁸ = 97128523 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (97128709) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29582 + ... + 32700.

It is an arithmetic number, because the mean of its divisors is an integer number (7020000).

Almost surely, 2^97128779 is an apocalyptic number.

97128779 is a deficient number, since it is larger than the sum of its proper divisors (15191221).

97128779 is a wasteful number, since it uses less digits than its factorization.

97128779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3298.

The product of its digits is 444528, while the sum is 50.

The square root of 97128779 is about 9855.3933965114. The cubic root of 97128779 is about 459.6733329761.

The spelling of 97128779 in words is "ninety-seven million, one hundred twenty-eight thousand, seven hundred seventy-nine".