97785591 has 4 divisors (see below), whose sum is σ = 130380792. Its totient is φ = 65190392.

The previous prime is 97785559. The next prime is 97785599. The reversal of 97785591 is 19558779.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19558779 = 3 ⋅6519593.

It is a cyclic number.

It is not a de Polignac number, because 97785591 - 2⁵ = 97785559 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (97785599) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16297596 + ... + 16297601.

It is an arithmetic number, because the mean of its divisors is an integer number (32595198).

Almost surely, 2^97785591 is an apocalyptic number.

97785591 is a deficient number, since it is larger than the sum of its proper divisors (32595201).

97785591 is a wasteful number, since it uses less digits than its factorization.

97785591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32595200.

The product of its digits is 793800, while the sum is 51.

The square root of 97785591 is about 9888.6597170699. The cubic root of 97785591 is about 460.7071527358.

It can be divided in two parts, 977 and 85591, that added together give a palindrome (86568).

The spelling of 97785591 in words is "ninety-seven million, seven hundred eighty-five thousand, five hundred ninety-one".