999521915173 has 8 divisors (see below), whose sum is σ = 1034000524800. Its totient is φ = 965044128048.

The previous prime is 999521915149. The next prime is 999521915239. The reversal of 999521915173 is 371519125999.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-999521915173 is a prime.

It is a super-2 number, since 2×999521915173² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999521915123) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3252940 + ... + 3546922.

It is an arithmetic number, because the mean of its divisors is an integer number (129250065600).

Almost surely, 2^999521915173 is an apocalyptic number.

It is an amenable number.

999521915173 is a deficient number, since it is larger than the sum of its proper divisors (34478609627).

999521915173 is a wasteful number, since it uses less digits than its factorization.

999521915173 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 411251.

The product of its digits is 6889050, while the sum is 61.

The spelling of 999521915173 in words is "nine hundred ninety-nine billion, five hundred twenty-one million, nine hundred fifteen thousand, one hundred seventy-three".