1999958 has 4 divisors (see below), whose sum is σ = 2999940. Its totient is φ = 999978.

The previous prime is 1999957. The next prime is 1999969. The reversal of 1999958 is 8599991.

It is a semiprime because it is the product of two primes.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1999957) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499988 + ... + 499991.

It is an arithmetic number, because the mean of its divisors is an integer number (749985).

2^1999958 is an apocalyptic number.

1999958 is a deficient number, since it is larger than the sum of its proper divisors (999982).

1999958 is an equidigital number, since it uses as much as digits as its factorization.

1999958 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 999981.

The product of its digits is 262440, while the sum is 50.

The square root of 1999958 is about 1414.1987130527. The cubic root of 1999958 is about 125.9912230386.

The spelling of 1999958 in words is "one million, nine hundred ninety-nine thousand, nine hundred fifty-eight".