1955999 has 4 divisors (see below), whose sum is σ = 1997664. Its totient is φ = 1914336.

The previous prime is 1955983. The next prime is 1956001. The reversal of 1955999 is 9995591.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9995591 = 439 ⋅22769.

It is a cyclic number.

It is not a de Polignac number, because 1955999 - 2⁴ = 1955983 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (47), and also a Moran number because the ratio is a prime number: 41617 = 1955999 / (1 + 9 + 5 + 5 + 9 + 9 + 9).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1955939) 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, 20762 + ... + 20855.

It is an arithmetic number, because the mean of its divisors is an integer number (499416).

2^1955999 is an apocalyptic number.

1955999 is a deficient number, since it is larger than the sum of its proper divisors (41665).

1955999 is an equidigital number, since it uses as much as digits as its factorization.

1955999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41664.

The product of its digits is 164025, while the sum is 47.

The square root of 1955999 is about 1398.5703414559. The cubic root of 1955999 is about 125.0612819513.

The spelling of 1955999 in words is "one million, nine hundred fifty-five thousand, nine hundred ninety-nine".