1977823 has 2 divisors, whose sum is σ = 1977824. Its totient is φ = 1977822.

The previous prime is 1977821. The next prime is 1977827. The reversal of 1977823 is 3287791.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1977823 - 2¹ = 1977821 is a prime.

Together with 1977821, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1977821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 988911 + 988912.

It is an arithmetic number, because the mean of its divisors is an integer number (988912).

2^1977823 is an apocalyptic number.

1977823 is a deficient number, since it is larger than the sum of its proper divisors (1).

1977823 is an equidigital number, since it uses as much as digits as its factorization.

1977823 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 21168, while the sum is 37.

The square root of 1977823 is about 1406.3509519320. The cubic root of 1977823 is about 125.5246852285.

Adding to 1977823 its product of digits (21168), we get a palindrome (1998991).

The spelling of 1977823 in words is "one million, nine hundred seventy-seven thousand, eight hundred twenty-three".