1965890 has 16 divisors (see below), whose sum is σ = 3588408. Its totient is φ = 775296.

The previous prime is 1965889. The next prime is 1965893. The reversal of 1965890 is 985691.

It can be written as a sum of positive squares in 4 ways, for example, as 1555009 + 410881 = 1247^2 + 641^2 .

It is not an unprimeable number, because it can be changed into a prime (1965893) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 617 + ... + 2076.

2^1965890 is an apocalyptic number.

1965890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1965890 is a deficient number, since it is larger than the sum of its proper divisors (1622518).

1965890 is a wasteful number, since it uses less digits than its factorization.

1965890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2773.

The product of its (nonzero) digits is 19440, while the sum is 38.

The square root of 1965890 is about 1402.1019934370. The cubic root of 1965890 is about 125.2717288793.

It can be divided in two parts, 196 and 5890, that multiplied together give a triangular number (1154440 = T₁₅₁₉).

The spelling of 1965890 in words is "one million, nine hundred sixty-five thousand, eight hundred ninety".