99999999637 has 4 divisors (see below), whose sum is σ = 100884955500. Its totient is φ = 99115043776.

The previous prime is 99999999599. The next prime is 99999999647. The reversal of 99999999637 is 73699999999.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 73699999999 = 71 ⋅1038028169.

It can be written as a sum of positive squares in 2 ways, for example, as 13030450801 + 86969548836 = 114151^2 + 294906^2 .

It is a cyclic number.

It is not a de Polignac number, because 99999999637 - 2¹⁹ = 99999475349 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 (99999999647) 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, 442477762 + ... + 442477987.

It is an arithmetic number, because the mean of its divisors is an integer number (25221238875).

Almost surely, 2^99999999637 is an apocalyptic number.

It is an amenable number.

99999999637 is a deficient number, since it is larger than the sum of its proper divisors (884955863).

99999999637 is a wasteful number, since it uses less digits than its factorization.

99999999637 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 884955862.

The product of its digits is 5423886846, while the sum is 88.

The spelling of 99999999637 in words is "ninety-nine billion, nine hundred ninety-nine million, nine hundred ninety-nine thousand, six hundred thirty-seven".