1640466 has 32 divisors (see below), whose sum is σ = 3862080. Its totient is φ = 514368.

The previous prime is 1640461. The next prime is 1640467. The reversal of 1640466 is 6640461.

It is a super-2 number, since 2×1640466² = 5382257394312, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (1640461) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25 + ... + 1811.

It is an arithmetic number, because the mean of its divisors is an integer number (120690).

2^1640466 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1640466, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1931040).

1640466 is an abundant number, since it is smaller than the sum of its proper divisors (2221614).

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

1640466 is a wasteful number, since it uses less digits than its factorization.

1640466 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1815 (or 1809 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 1640466 is about 1280.8067769964. The cubic root of 1640466 is about 117.9385392853.

The spelling of 1640466 in words is "one million, six hundred forty thousand, four hundred sixty-six".