1778961 has 4 divisors (see below), whose sum is σ = 2371952. Its totient is φ = 1185972.

The previous prime is 1778929. The next prime is 1778963. The reversal of 1778961 is 1698771.

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 1778961 - 2⁵ = 1778929 is a prime.

It is a D-number.

It is a Duffinian number.

1778961 is a lucky number.

It is a plaindrome in base 14.

It is not an unprimeable number, because it can be changed into a prime (1778963) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 296491 + ... + 296496.

It is an arithmetic number, because the mean of its divisors is an integer number (592988).

2^1778961 is an apocalyptic number.

It is an amenable number.

1778961 is a deficient number, since it is larger than the sum of its proper divisors (592991).

1778961 is an equidigital number, since it uses as much as digits as its factorization.

1778961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 592990.

The product of its digits is 21168, while the sum is 39.

The square root of 1778961 is about 1333.7769678623. The cubic root of 1778961 is about 121.1682426135.

The spelling of 1778961 in words is "one million, seven hundred seventy-eight thousand, nine hundred sixty-one".