1918641 has 4 divisors (see below), whose sum is σ = 2558192. Its totient is φ = 1279092.

The previous prime is 1918607. The next prime is 1918643. The reversal of 1918641 is 1468191.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 1918641 - 2⁹ = 1918129 is a prime.

It is a D-number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1918599 and 1918608.

It is not an unprimeable number, because it can be changed into a prime (1918643) 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 3 ways as a sum of consecutive naturals, for example, 319771 + ... + 319776.

It is an arithmetic number, because the mean of its divisors is an integer number (639548).

2^1918641 is an apocalyptic number.

It is an amenable number.

1918641 is a deficient number, since it is larger than the sum of its proper divisors (639551).

1918641 is an equidigital number, since it uses as much as digits as its factorization.

1918641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 639550.

The product of its digits is 1728, while the sum is 30.

The square root of 1918641 is about 1385.1501723640. The cubic root of 1918641 is about 124.2599688099.

The spelling of 1918641 in words is "one million, nine hundred eighteen thousand, six hundred forty-one".