1640766 has 16 divisors (see below), whose sum is σ = 3305088. Its totient is φ = 543000.

The previous prime is 1640761. The next prime is 1640773. The reversal of 1640766 is 6670461.

1640766 is a nontrivial binomial coefficient, being equal to C(1812, 2).

It is a super-2 number, since 2×1640766² = 5384226133512, 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 (1640761) 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, 1 + ... + 1811.

It is an arithmetic number, because the mean of its divisors is an integer number (206568).

2^1640766 is an apocalyptic number.

1640766 is the 1811-st triangular number and also the 906-th hexagonal number.

1640766 is an abundant number, since it is smaller than the sum of its proper divisors (1664322).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1640766 is a wasteful number, since it uses less digits than its factorization.

1640766 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1967.

The product of its (nonzero) digits is 6048, while the sum is 30.

The square root of 1640766 is about 1280.9238853265. The cubic root of 1640766 is about 117.9457281786.

It can be divided in two parts, 16 and 40766, that multiplied together give a palindrome (652256).

The spelling of 1640766 in words is "one million, six hundred forty thousand, seven hundred sixty-six".