1780642 has 16 divisors (see below), whose sum is σ = 2874240. Its totient is φ = 824688.

The previous prime is 1780633. The next prime is 1780643. The reversal of 1780642 is 2460871.

It is a self number, because there is not a number n which added to its sum of digits gives 1780642.

It is not an unprimeable number, because it can be changed into a prime (1780643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1288 + ... + 2284.

It is an arithmetic number, because the mean of its divisors is an integer number (179640).

2^1780642 is an apocalyptic number.

1780642 is a deficient number, since it is larger than the sum of its proper divisors (1093598).

1780642 is a wasteful number, since it uses less digits than its factorization.

1780642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1065.

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 1780642 is about 1334.4069843942. The cubic root of 1780642 is about 121.2063959127.

The spelling of 1780642 in words is "one million, seven hundred eighty thousand, six hundred forty-two".