989928817 has 2 divisors, whose sum is σ = 989928818. Its totient is φ = 989928816.

The previous prime is 989928787. The next prime is 989928839. The reversal of 989928817 is 718829989.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 859603761 + 130325056 = 29319^2 + 11416^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-989928817 is a prime.

It is not a weakly prime, because it can be changed into another prime (989928847) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 494964408 + 494964409.

It is an arithmetic number, because the mean of its divisors is an integer number (494964409).

Almost surely, 2^989928817 is an apocalyptic number.

It is an amenable number.

989928817 is a deficient number, since it is larger than the sum of its proper divisors (1).

989928817 is an equidigital number, since it uses as much as digits as its factorization.

989928817 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5225472, while the sum is 61.

The square root of 989928817 is about 31463.1342526456. The cubic root of 989928817 is about 996.6316056589.

The spelling of 989928817 in words is "nine hundred eighty-nine million, nine hundred twenty-eight thousand, eight hundred seventeen".