1999965 has 64 divisors (see below), whose sum is σ = 3981312. Its totient is φ = 844800.

The previous prime is 1999957. The next prime is 1999969. The reversal of 1999965 is 5699991.

It is a happy number.

It is not a de Polignac number, because 1999965 - 2³ = 1999957 is a prime.

Its product of digits (196830) is a multiple of the sum of its prime divisors (90).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1999969) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 64500 + ... + 64530.

It is an arithmetic number, because the mean of its divisors is an integer number (62208).

2^1999965 is an apocalyptic number.

1999965 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1999965 is a deficient number, since it is larger than the sum of its proper divisors (1981347).

1999965 is a wasteful number, since it uses less digits than its factorization.

1999965 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90.

The product of its digits is 196830, while the sum is 48.

The square root of 1999965 is about 1414.2011879503. The cubic root of 1999965 is about 125.9913700313.

The spelling of 1999965 in words is "one million, nine hundred ninety-nine thousand, nine hundred sixty-five".