991053361 has 3 divisors (see below), whose sum is σ = 991084843. Its totient is φ = 991021880.

The previous prime is 991053313. The next prime is 991053407. The reversal of 991053361 is 163350199.

The square root of 991053361 is 31481.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 163350199 = 857 ⋅190607.

It can be written as a sum of positive squares in only one way, i.e., 59582961 + 931470400 = 7719^2 + 30520^2 .

It is not a de Polignac number, because 991053361 - 2⁹ = 991052849 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 991053361.

It is not an unprimeable number, because it can be changed into a prime (991053311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 15741 + ... + 47221.

Almost surely, 2^991053361 is an apocalyptic number.

991053361 is the 31481-st square number.

991053361 is the 15741-st centered octagonal number.

It is an amenable number.

991053361 is a deficient number, since it is larger than the sum of its proper divisors (31482).

991053361 is an frugal number, since it uses more digits than its factorization.

991053361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62962 (or 31481 counting only the distinct ones).

The product of its (nonzero) digits is 21870, while the sum is 37.

The cubic root of 991053361 is about 997.0088489359.

The spelling of 991053361 in words is "nine hundred ninety-one million, fifty-three thousand, three hundred sixty-one".