9977521 has 8 divisors (see below), whose sum is σ = 10622664. Its totient is φ = 9338880.

The previous prime is 9977519. The next prime is 9977551. The reversal of 9977521 is 1257799.

9977521 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 4389025 + 5588496 = 2095^2 + 2364^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 9977521 - 2¹ = 9977519 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (9977551) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1761 + ... + 4801.

It is an arithmetic number, because the mean of its divisors is an integer number (1327833).

Almost surely, 2^9977521 is an apocalyptic number.

It is an amenable number.

9977521 is a deficient number, since it is larger than the sum of its proper divisors (645143).

9977521 is a wasteful number, since it uses less digits than its factorization.

9977521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3251.

The product of its digits is 39690, while the sum is 40.

The square root of 9977521 is about 3158.7214185490. The cubic root of 9977521 is about 215.2819160997.

The spelling of 9977521 in words is "nine million, nine hundred seventy-seven thousand, five hundred twenty-one".