991170001 has 2 divisors, whose sum is σ = 991170002. Its totient is φ = 991170000.

The previous prime is 991169951. The next prime is 991170007. The reversal of 991170001 is 100071199.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 989417025 + 1752976 = 31455^2 + 1324^2 .

It is a cyclic number.

It is not a de Polignac number, because 991170001 - 2⁹ = 991169489 is a prime.

It is not a weakly prime, because it can be changed into another prime (991170007) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495585000 + 495585001.

It is an arithmetic number, because the mean of its divisors is an integer number (495585001).

Almost surely, 2^991170001 is an apocalyptic number.

It is an amenable number.

991170001 is a deficient number, since it is larger than the sum of its proper divisors (1).

991170001 is an equidigital number, since it uses as much as digits as its factorization.

991170001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 567, while the sum is 28.

The square root of 991170001 is about 31482.8524914754. The cubic root of 991170001 is about 997.0479610412.

The spelling of 991170001 in words is "nine hundred ninety-one million, one hundred seventy thousand, one".