1999973 has 4 divisors (see below), whose sum is σ = 2046528. Its totient is φ = 1953420.

The previous prime is 1999969. The next prime is 1999979. The reversal of 1999973 is 3799991.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1999973 - 2² = 1999969 is a prime.

It is a Duffinian number.

It is a plaindrome in base 11.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1999979) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23213 + ... + 23298.

It is an arithmetic number, because the mean of its divisors is an integer number (511632).

2^1999973 is an apocalyptic number.

It is an amenable number.

1999973 is a deficient number, since it is larger than the sum of its proper divisors (46555).

1999973 is an equidigital number, since it uses as much as digits as its factorization.

1999973 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46554.

The product of its digits is 137781, while the sum is 47.

The square root of 1999973 is about 1414.2040163993. The cubic root of 1999973 is about 125.9915380225.

The spelling of 1999973 in words is "one million, nine hundred ninety-nine thousand, nine hundred seventy-three".