989928851 has 2 divisors, whose sum is σ = 989928852. Its totient is φ = 989928850.

The previous prime is 989928847. The next prime is 989928869. The reversal of 989928851 is 158829989.

It is a weak prime.

It is an emirp because it is prime and its reverse (158829989) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 989928851 - 2² = 989928847 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (989928871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 494964425 + 494964426.

It is an arithmetic number, because the mean of its divisors is an integer number (494964426).

Almost surely, 2^989928851 is an apocalyptic number.

989928851 is a deficient number, since it is larger than the sum of its proper divisors (1).

989928851 is an equidigital number, since it uses as much as digits as its factorization.

989928851 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3732480, while the sum is 59.

The square root of 989928851 is about 31463.1347929605. The cubic root of 989928851 is about 996.6316170690.

The spelling of 989928851 in words is "nine hundred eighty-nine million, nine hundred twenty-eight thousand, eight hundred fifty-one".