987773238521 has 2 divisors, whose sum is σ = 987773238522. Its totient is φ = 987773238520.

The previous prime is 987773238479. The next prime is 987773238547. The reversal of 987773238521 is 125832377789.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 787842636025 + 199930602496 = 887605^2 + 447136^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-987773238521 is a prime.

It is not a weakly prime, because it can be changed into another prime (987773238421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 493886619260 + 493886619261.

It is an arithmetic number, because the mean of its divisors is an integer number (493886619261).

Almost surely, 2^987773238521 is an apocalyptic number.

It is an amenable number.

987773238521 is a deficient number, since it is larger than the sum of its proper divisors (1).

987773238521 is an equidigital number, since it uses as much as digits as its factorization.

987773238521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 35562240, while the sum is 62.

The spelling of 987773238521 in words is "nine hundred eighty-seven billion, seven hundred seventy-three million, two hundred thirty-eight thousand, five hundred twenty-one".