988805821 has 2 divisors, whose sum is σ = 988805822. Its totient is φ = 988805820.

The previous prime is 988805813. The next prime is 988805827. The reversal of 988805821 is 128508889.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 755480196 + 233325625 = 27486^2 + 15275^2 .

It is a cyclic number.

It is not a de Polignac number, because 988805821 - 2³ = 988805813 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (988805827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 494402910 + 494402911.

It is an arithmetic number, because the mean of its divisors is an integer number (494402911).

Almost surely, 2^988805821 is an apocalyptic number.

It is an amenable number.

988805821 is a deficient number, since it is larger than the sum of its proper divisors (1).

988805821 is an equidigital number, since it uses as much as digits as its factorization.

988805821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 368640, while the sum is 49.

The square root of 988805821 is about 31445.2829689923. The cubic root of 988805821 is about 996.2545964659.

The spelling of 988805821 in words is "nine hundred eighty-eight million, eight hundred five thousand, eight hundred twenty-one".