9990388517 has 2 divisors, whose sum is σ = 9990388518. Its totient is φ = 9990388516.

The previous prime is 9990388483. The next prime is 9990388523. The reversal of 9990388517 is 7158830999.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8499733636 + 1490654881 = 92194^2 + 38609^2 .

It is a cyclic number.

It is not a de Polignac number, because 9990388517 - 2¹² = 9990384421 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9990384517) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4995194258 + 4995194259.

It is an arithmetic number, because the mean of its divisors is an integer number (4995194259).

Almost surely, 2^9990388517 is an apocalyptic number.

It is an amenable number.

9990388517 is a deficient number, since it is larger than the sum of its proper divisors (1).

9990388517 is an equidigital number, since it uses as much as digits as its factorization.

9990388517 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4898880, while the sum is 59.

The square root of 9990388517 is about 99951.9310318715. The cubic root of 9990388517 is about 2153.7442250249.

The spelling of 9990388517 in words is "nine billion, nine hundred ninety million, three hundred eighty-eight thousand, five hundred seventeen".