1820642 has 8 divisors (see below), whose sum is σ = 2739036. Its totient is φ = 907632.

The previous prime is 1820641. The next prime is 1820647. The reversal of 1820642 is 2460281.

It can be written as a sum of positive squares in 2 ways, for example, as 1819801 + 841 = 1349^2 + 29^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (1820641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 353 + ... + 1940.

2^1820642 is an apocalyptic number.

1820642 is a deficient number, since it is larger than the sum of its proper divisors (918394).

1820642 is a wasteful number, since it uses less digits than its factorization.

1820642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2692.

The product of its (nonzero) digits is 768, while the sum is 23.

The square root of 1820642 is about 1349.3116763743. The cubic root of 1820642 is about 122.1072692671.

The spelling of 1820642 in words is "one million, eight hundred twenty thousand, six hundred forty-two".