987940681309 has 2 divisors, whose sum is σ = 987940681310. Its totient is φ = 987940681308.

The previous prime is 987940681261. The next prime is 987940681327. The reversal of 987940681309 is 903186049789.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 623788778809 + 364151902500 = 789803^2 + 603450^2 .

It is a cyclic number.

It is not a de Polignac number, because 987940681309 - 2⁷ = 987940681181 is a prime.

It is a super-2 number, since 2×987940681309² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (987940684309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 493970340654 + 493970340655.

It is an arithmetic number, because the mean of its divisors is an integer number (493970340655).

Almost surely, 2^987940681309 is an apocalyptic number.

It is an amenable number.

987940681309 is a deficient number, since it is larger than the sum of its proper divisors (1).

987940681309 is an equidigital number, since it uses as much as digits as its factorization.

987940681309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23514624, while the sum is 64.

The spelling of 987940681309 in words is "nine hundred eighty-seven billion, nine hundred forty million, six hundred eighty-one thousand, three hundred nine".