1987195549 has 4 divisors (see below), whose sum is σ = 2001700764. Its totient is φ = 1972690336.

The previous prime is 1987195531. The next prime is 1987195559. The reversal of 1987195549 is 9455917891.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1130169924 + 857025625 = 33618^2 + 29275^2 .

It is a cyclic number.

It is not a de Polignac number, because 1987195549 - 2⁹ = 1987195037 is a prime.

It is a super-2 number, since 2×1987195549² = 7897892299930822802, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1987195493 and 1987195502.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1987195559) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7252402 + ... + 7252675.

It is an arithmetic number, because the mean of its divisors is an integer number (500425191).

Almost surely, 2^1987195549 is an apocalyptic number.

It is an amenable number.

1987195549 is a deficient number, since it is larger than the sum of its proper divisors (14505215).

1987195549 is a wasteful number, since it uses less digits than its factorization.

1987195549 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14505214.

The product of its digits is 4082400, while the sum is 58.

The square root of 1987195549 is about 44577.9715666830. The cubic root of 1987195549 is about 1257.2265251446.

The spelling of 1987195549 in words is "one billion, nine hundred eighty-seven million, one hundred ninety-five thousand, five hundred forty-nine".