9999997544 has 8 divisors (see below), whose sum is σ = 18749995410. Its totient is φ = 4999998768.

The previous prime is 9999997543. The next prime is 9999997549. The reversal of 9999997544 is 4457999999.

It can be written as a sum of positive squares in only one way, i.e., 5312952100 + 4687045444 = 72890^2 + 68462^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a nialpdrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (9999997543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 624999839 + ... + 624999854.

Almost surely, 2^9999997544 is an apocalyptic number.

It is an amenable number.

9999997544 is a deficient number, since it is larger than the sum of its proper divisors (8749997866).

9999997544 is a wasteful number, since it uses less digits than its factorization.

9999997544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1249999699 (or 1249999695 counting only the distinct ones).

The product of its digits is 297606960, while the sum is 74.

The square root of 9999997544 is about 99999.9877199992. The cubic root of 9999997544 is about 2154.4345136555.

The spelling of 9999997544 in words is "nine billion, nine hundred ninety-nine million, nine hundred ninety-seven thousand, five hundred forty-four".