999789972 has 24 divisors (see below), whose sum is σ = 2344690656. Its totient is φ = 331570848.

The previous prime is 999789953. The next prime is 999789983. The reversal of 999789972 is 279987999.

It is a super-2 number, since 2×999789972² = 1999159976223521568, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 999789897 and 999789906.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 209098 + ... + 213825.

It is an arithmetic number, because the mean of its divisors is an integer number (97695444).

Almost surely, 2^999789972 is an apocalyptic number.

It is an amenable number.

999789972 is an abundant number, since it is smaller than the sum of its proper divisors (1344900684).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

999789972 is a wasteful number, since it uses less digits than its factorization.

999789972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 423127 (or 423125 counting only the distinct ones).

The product of its digits is 46294416, while the sum is 69.

The square root of 999789972 is about 31619.4555930364. The cubic root of 999789972 is about 999.9299857648.

The spelling of 999789972 in words is "nine hundred ninety-nine million, seven hundred eighty-nine thousand, nine hundred seventy-two".