1988517 has 4 divisors (see below), whose sum is σ = 2651360. Its totient is φ = 1325676.

The previous prime is 1988513. The next prime is 1988531. The reversal of 1988517 is 7158891.

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 1988517 - 2² = 1988513 is a prime.

It is a D-number.

It is a Duffinian number.

1988517 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1988513) 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, 331417 + ... + 331422.

It is an arithmetic number, because the mean of its divisors is an integer number (662840).

2^1988517 is an apocalyptic number.

It is an amenable number.

1988517 is a deficient number, since it is larger than the sum of its proper divisors (662843).

1988517 is an equidigital number, since it uses as much as digits as its factorization.

1988517 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 662842.

The product of its digits is 20160, while the sum is 39.

The square root of 1988517 is about 1410.1478645873. The cubic root of 1988517 is about 125.7505141430.

It can be divided in two parts, 198 and 8517, that multiplied together give a triangular number (1686366 = T₁₈₃₆).

The spelling of 1988517 in words is "one million, nine hundred eighty-eight thousand, five hundred seventeen".