1998977 has 2 divisors, whose sum is σ = 1998978. Its totient is φ = 1998976.

The previous prime is 1998961. The next prime is 1998991. The reversal of 1998977 is 7798991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1915456 + 83521 = 1384^2 + 289^2 .

It is an emirp because it is prime and its reverse (7798991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1998977 - 2⁴ = 1998961 is a prime.

It is not a weakly prime, because it can be changed into another prime (1998917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 999488 + 999489.

It is an arithmetic number, because the mean of its divisors is an integer number (999489).

2^1998977 is an apocalyptic number.

It is an amenable number.

1998977 is a deficient number, since it is larger than the sum of its proper divisors (1).

1998977 is an equidigital number, since it uses as much as digits as its factorization.

1998977 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 285768, while the sum is 50.

The square root of 1998977 is about 1413.8518309922. The cubic root of 1998977 is about 125.9706196719.

The spelling of 1998977 in words is "one million, nine hundred ninety-eight thousand, nine hundred seventy-seven".