1640851 has 2 divisors, whose sum is σ = 1640852. Its totient is φ = 1640850.

The previous prime is 1640833. The next prime is 1640869. The reversal of 1640851 is 1580461.

It is a balanced prime because it is at equal distance from previous prime (1640833) and next prime (1640869).

It is an emirp because it is prime and its reverse (1580461) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1640851 - 2⁵ = 1640819 is a prime.

It is an Ulam number.

It is not a weakly prime, because it can be changed into another prime (1140851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 820425 + 820426.

It is an arithmetic number, because the mean of its divisors is an integer number (820426).

2^1640851 is an apocalyptic number.

1640851 is a deficient number, since it is larger than the sum of its proper divisors (1).

1640851 is an equidigital number, since it uses as much as digits as its factorization.

1640851 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 960, while the sum is 25.

The square root of 1640851 is about 1280.9570640736. The cubic root of 1640851 is about 117.9477648724.

The spelling of 1640851 in words is "one million, six hundred forty thousand, eight hundred fifty-one".