1987681417 has 4 divisors (see below), whose sum is σ = 2008173076. Its totient is φ = 1967189760.

The previous prime is 1987681391. The next prime is 1987681439. The reversal of 1987681417 is 7141867891.

It is a happy number.

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 1037870656 + 949810761 = 32216^2 + 30819^2 .

It is a cyclic number.

It is not a de Polignac number, because 1987681417 - 2¹⁹ = 1987157129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1987681217) 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, 10245684 + ... + 10245877.

It is an arithmetic number, because the mean of its divisors is an integer number (502043269).

Almost surely, 2^1987681417 is an apocalyptic number.

It is an amenable number.

1987681417 is a deficient number, since it is larger than the sum of its proper divisors (20491659).

1987681417 is an equidigital number, since it uses as much as digits as its factorization.

1987681417 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20491658.

The product of its digits is 677376, while the sum is 52.

The square root of 1987681417 is about 44583.4208759265. The cubic root of 1987681417 is about 1257.3289804801.

The spelling of 1987681417 in words is "one billion, nine hundred eighty-seven million, six hundred eighty-one thousand, four hundred seventeen".