999997172 has 6 divisors (see below), whose sum is σ = 1749995058. Its totient is φ = 499998584.

The previous prime is 999997133. The next prime is 999997181. The reversal of 999997172 is 271799999.

It can be written as a sum of positive squares in only one way, i.e., 724901776 + 275095396 = 26924^2 + 16586^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 124999643 + ... + 124999650.

It is an arithmetic number, because the mean of its divisors is an integer number (291665843).

Almost surely, 2^999997172 is an apocalyptic number.

It is an amenable number.

999997172 is a deficient number, since it is larger than the sum of its proper divisors (749997886).

999997172 is a wasteful number, since it uses less digits than its factorization.

999997172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 249999297 (or 249999295 counting only the distinct ones).

The product of its digits is 5786802, while the sum is 62.

The square root of 999997172 is about 31622.7318870461. The cubic root of 999997172 is about 999.9990573324. Note that the first 3 decimals are identical.

The spelling of 999997172 in words is "nine hundred ninety-nine million, nine hundred ninety-seven thousand, one hundred seventy-two".