99615221549 has 4 divisors (see below), whose sum is σ = 100249713564. Its totient is φ = 98980729536.

The previous prime is 99615221513. The next prime is 99615221567. The reversal of 99615221549 is 94512251699.

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 49161975625 + 50453245924 = 221725^2 + 224618^2 .

It is a cyclic number.

It is not a de Polignac number, because 99615221549 - 2¹⁶ = 99615156013 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 99615221549.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99615221569) 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, 317245772 + ... + 317246085.

It is an arithmetic number, because the mean of its divisors is an integer number (25062428391).

Almost surely, 2^99615221549 is an apocalyptic number.

It is an amenable number.

99615221549 is a deficient number, since it is larger than the sum of its proper divisors (634492015).

99615221549 is a wasteful number, since it uses less digits than its factorization.

99615221549 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 634492014.

The product of its digits is 1749600, while the sum is 53.

The spelling of 99615221549 in words is "ninety-nine billion, six hundred fifteen million, two hundred twenty-one thousand, five hundred forty-nine".