99105751621 has 4 divisors (see below), whose sum is σ = 99124782700. Its totient is φ = 99086720544.

The previous prime is 99105751597. The next prime is 99105751627. The reversal of 99105751621 is 12615750199.

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

It can be written as a sum of positive squares in 2 ways, for example, as 46909495396 + 52196256225 = 216586^2 + 228465^2 .

It is a cyclic number.

It is not a de Polignac number, because 99105751621 - 2¹⁵ = 99105718853 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 (99105751627) 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, 9507726 + ... + 9518143.

It is an arithmetic number, because the mean of its divisors is an integer number (24781195675).

Almost surely, 2^99105751621 is an apocalyptic number.

It is an amenable number.

99105751621 is a deficient number, since it is larger than the sum of its proper divisors (19031079).

99105751621 is a wasteful number, since it uses less digits than its factorization.

99105751621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19031078.

The product of its (nonzero) digits is 170100, while the sum is 46.

The spelling of 99105751621 in words is "ninety-nine billion, one hundred five million, seven hundred fifty-one thousand, six hundred twenty-one".