1987988 has 6 divisors (see below), whose sum is σ = 3478986. Its totient is φ = 993992.

The previous prime is 1987987. The next prime is 1987991. The reversal of 1987988 is 8897891.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 1119364 + 868624 = 1058^2 + 932^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1987981) 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 as a sum of consecutive naturals, namely, 248495 + ... + 248502.

It is an arithmetic number, because the mean of its divisors is an integer number (579831).

2^1987988 is an apocalyptic number.

It is an amenable number.

1987988 is a deficient number, since it is larger than the sum of its proper divisors (1490998).

1987988 is a wasteful number, since it uses less digits than its factorization.

1987988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 497001 (or 496999 counting only the distinct ones).

The product of its digits is 290304, while the sum is 50.

The square root of 1987988 is about 1409.9602831286. The cubic root of 1987988 is about 125.7393621267.

Subtracting 1987988 from its reverse (8897891), we obtain a triangular number (6909903 = T₃₇₁₇).

The spelling of 1987988 in words is "one million, nine hundred eighty-seven thousand, nine hundred eighty-eight".