987231517 has 2 divisors, whose sum is σ = 987231518. Its totient is φ = 987231516.

The previous prime is 987231491. The next prime is 987231529. The reversal of 987231517 is 715132789.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 816302041 + 170929476 = 28571^2 + 13074^2 .

It is a cyclic number.

It is not a de Polignac number, because 987231517 - 2⁷ = 987231389 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (987234517) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 493615758 + 493615759.

It is an arithmetic number, because the mean of its divisors is an integer number (493615759).

Almost surely, 2^987231517 is an apocalyptic number.

It is an amenable number.

987231517 is a deficient number, since it is larger than the sum of its proper divisors (1).

987231517 is an equidigital number, since it uses as much as digits as its factorization.

987231517 is an evil number, because the sum of its binary digits is even.

The product of its digits is 105840, while the sum is 43.

The square root of 987231517 is about 31420.2405624145. The cubic root of 987231517 is about 995.7255944894.

The spelling of 987231517 in words is "nine hundred eighty-seven million, two hundred thirty-one thousand, five hundred seventeen".