99859661 has 4 divisors (see below), whose sum is σ = 108937824. Its totient is φ = 90781500.

The previous prime is 99859637. The next prime is 99859679. The reversal of 99859661 is 16695899.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-99859661 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99859621) 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, 4539065 + ... + 4539086.

It is an arithmetic number, because the mean of its divisors is an integer number (27234456).

Almost surely, 2^99859661 is an apocalyptic number.

It is an amenable number.

99859661 is a deficient number, since it is larger than the sum of its proper divisors (9078163).

99859661 is a wasteful number, since it uses less digits than its factorization.

99859661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9078162.

The product of its digits is 1049760, while the sum is 53.

The square root of 99859661 is about 9992.9805863916. The cubic root of 99859661 is about 463.9416497300.

The spelling of 99859661 in words is "ninety-nine million, eight hundred fifty-nine thousand, six hundred sixty-one".