988721 has 4 divisors (see below), whose sum is σ = 999012. Its totient is φ = 978432.

The previous prime is 988711. The next prime is 988727. The reversal of 988721 is 127889.

988721 = 49² + 50² + ... + 145².

It is a happy number.

988721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 579121 + 409600 = 761^2 + 640^2 .

It is a cyclic number.

It is not a de Polignac number, because 988721 - 2¹⁰ = 987697 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 988721.

It is not an unprimeable number, because it can be changed into a prime (988727) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5000 + ... + 5193.

It is an arithmetic number, because the mean of its divisors is an integer number (249753).

2⁹⁸⁸⁷²¹ is an apocalyptic number.

It is an amenable number.

988721 is a deficient number, since it is larger than the sum of its proper divisors (10291).

988721 is a wasteful number, since it uses less digits than its factorization.

988721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10290.

The product of its digits is 8064, while the sum is 35.

The square root of 988721 is about 994.3445077034. The cubic root of 988721 is about 99.6226108996.

The spelling of 988721 in words is "nine hundred eighty-eight thousand, seven hundred twenty-one".