999789973 has 36 divisors (see below), whose sum is σ = 1269035460. Its totient is φ = 784982016.

The previous prime is 999789953. The next prime is 999789983. The reversal of 999789973 is 379987999.

It can be written as a sum of positive squares in 6 ways, for example, as 274995889 + 724794084 = 16583^2 + 26922^2 .

It is a de Polignac number, because none of the positive numbers 2^k-999789973 is a prime.

It is a super-2 number, since 2×999789973² = 1999159980222681458, which contains 22 as substring.

999789973 is a modest number, since divided by 89973 gives 9997 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999789953) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1299733 + ... + 1300501.

It is an arithmetic number, because the mean of its divisors is an integer number (35250985).

Almost surely, 2^999789973 is an apocalyptic number.

It is an amenable number.

999789973 is a deficient number, since it is larger than the sum of its proper divisors (269245487).

999789973 is a wasteful number, since it uses less digits than its factorization.

999789973 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 966 (or 946 counting only the distinct ones).

The product of its digits is 69441624, while the sum is 70.

The square root of 999789973 is about 31619.4556088494. The cubic root of 999789973 is about 999.9299860982.

It can be divided in two parts, 9997 and 89973, that multiplied together give a square (899460081 = 29991²).

The spelling of 999789973 in words is "nine hundred ninety-nine million, seven hundred eighty-nine thousand, nine hundred seventy-three".