99478974521 has 16 divisors (see below), whose sum is σ = 104090125008. Its totient is φ = 94976582400.

The previous prime is 99478974509. The next prime is 99478974523. The reversal of 99478974521 is 12547987499.

It can be written as a sum of positive squares in 8 ways, for example, as 8477805625 + 91001168896 = 92075^2 + 301664^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-99478974521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (99478974523) 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 15 ways as a sum of consecutive naturals, for example, 897851 + ... + 1002543.

It is an arithmetic number, because the mean of its divisors is an integer number (6505632813).

Almost surely, 2^99478974521 is an apocalyptic number.

It is an amenable number.

99478974521 is a deficient number, since it is larger than the sum of its proper divisors (4611150487).

99478974521 is a wasteful number, since it uses less digits than its factorization.

99478974521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105212.

The product of its digits is 45722880, while the sum is 65.

The spelling of 99478974521 in words is "ninety-nine billion, four hundred seventy-eight million, nine hundred seventy-four thousand, five hundred twenty-one".