1801965 has 32 divisors (see below), whose sum is σ = 3211776. Its totient is φ = 855360.

The previous prime is 1801931. The next prime is 1801967. The reversal of 1801965 is 5691081.

It is a happy number.

It is not a de Polignac number, because 1801965 - 2⁶ = 1801901 is a prime.

It is a super-2 number, since 2×1801965² = 6494155722450, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1801967) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10974 + ... + 11136.

It is an arithmetic number, because the mean of its divisors is an integer number (100368).

2^1801965 is an apocalyptic number.

1801965 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1801965 is a deficient number, since it is larger than the sum of its proper divisors (1409811).

1801965 is a wasteful number, since it uses less digits than its factorization.

1801965 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 249.

The product of its (nonzero) digits is 2160, while the sum is 30.

The square root of 1801965 is about 1342.3728990113. The cubic root of 1801965 is about 121.6882887282.

It can be divided in two parts, 180 and 1965, that added together give a triangular number (2145 = T₆₅).

The spelling of 1801965 in words is "one million, eight hundred one thousand, nine hundred sixty-five".