99997765 has 8 divisors (see below), whose sum is σ = 137139840. Its totient is φ = 68569872.

The previous prime is 99997759. The next prime is 99997769. The reversal of 99997765 is 56779999.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 99997765 - 2¹³ = 99989573 is a prime.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99997769) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1428505 + ... + 1428574.

It is an arithmetic number, because the mean of its divisors is an integer number (17142480).

Almost surely, 2^99997765 is an apocalyptic number.

It is an amenable number.

99997765 is a deficient number, since it is larger than the sum of its proper divisors (37142075).

99997765 is a wasteful number, since it uses less digits than its factorization.

99997765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2857091.

The product of its digits is 9644670, while the sum is 61.

The square root of 99997765 is about 9999.8882493756. Note that the first 3 decimals coincide. The cubic root of 99997765 is about 464.1554253518.

The spelling of 99997765 in words is "ninety-nine million, nine hundred ninety-seven thousand, seven hundred sixty-five".