991600901 has 2 divisors, whose sum is σ = 991600902. Its totient is φ = 991600900.

The previous prime is 991600847. The next prime is 991600913. The reversal of 991600901 is 109006199.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 765850276 + 225750625 = 27674^2 + 15025^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-991600901 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (991600991) 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 as a sum of consecutive naturals, namely, 495800450 + 495800451.

It is an arithmetic number, because the mean of its divisors is an integer number (495800451).

Almost surely, 2^991600901 is an apocalyptic number.

It is an amenable number.

991600901 is a deficient number, since it is larger than the sum of its proper divisors (1).

991600901 is an equidigital number, since it uses as much as digits as its factorization.

991600901 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4374, while the sum is 35.

The square root of 991600901 is about 31489.6951557172. The cubic root of 991600901 is about 997.1924252341.

The spelling of 991600901 in words is "nine hundred ninety-one million, six hundred thousand, nine hundred one".