97720055 has 4 divisors (see below), whose sum is σ = 117264072. Its totient is φ = 78176040.

The previous prime is 97720043. The next prime is 97720057. The reversal of 97720055 is 55002779.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 97720055 - 2⁴ = 97720039 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 97719997 and 97720024.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (97720057) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9772001 + ... + 9772010.

It is an arithmetic number, because the mean of its divisors is an integer number (29316018).

Almost surely, 2^97720055 is an apocalyptic number.

97720055 is a deficient number, since it is larger than the sum of its proper divisors (19544017).

97720055 is a wasteful number, since it uses less digits than its factorization.

97720055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19544016.

The product of its (nonzero) digits is 22050, while the sum is 35.

The square root of 97720055 is about 9885.3454669020. The cubic root of 97720055 is about 460.6042076043.

The spelling of 97720055 in words is "ninety-seven million, seven hundred twenty thousand, fifty-five".