991051225 has 6 divisors (see below), whose sum is σ = 1228903550. Its totient is φ = 792840960.

The previous prime is 991051177. The next prime is 991051241. The reversal of 991051225 is 522150199.

It can be written as a sum of positive squares in 3 ways, for example, as 3583449 + 987467776 = 1893^2 + 31424^2 .

It is not a de Polignac number, because 991051225 - 2⁷ = 991051097 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 19821000 + ... + 19821049.

Almost surely, 2^991051225 is an apocalyptic number.

It is an amenable number.

991051225 is a deficient number, since it is larger than the sum of its proper divisors (237852325).

991051225 is a wasteful number, since it uses less digits than its factorization.

991051225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39642059 (or 39642054 counting only the distinct ones).

The product of its (nonzero) digits is 8100, while the sum is 34.

The square root of 991051225 is about 31480.9660747570. The cubic root of 991051225 is about 997.0081326568.

The spelling of 991051225 in words is "nine hundred ninety-one million, fifty-one thousand, two hundred twenty-five".