998749639 has 2 divisors, whose sum is σ = 998749640. Its totient is φ = 998749638.

The previous prime is 998749579. The next prime is 998749657. The reversal of 998749639 is 936947899.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 998749639 - 2⁹ = 998749127 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (998747639) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499374819 + 499374820.

It is an arithmetic number, because the mean of its divisors is an integer number (499374820).

Almost surely, 2^998749639 is an apocalyptic number.

998749639 is a deficient number, since it is larger than the sum of its proper divisors (1).

998749639 is an equidigital number, since it uses as much as digits as its factorization.

998749639 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 26453952, while the sum is 64.

The square root of 998749639 is about 31603.0004746385. Note that the first 3 decimals coincide. The cubic root of 998749639 is about 999.5830391678.

The spelling of 998749639 in words is "nine hundred ninety-eight million, seven hundred forty-nine thousand, six hundred thirty-nine".