991671007 has 2 divisors, whose sum is σ = 991671008. Its totient is φ = 991671006.

The previous prime is 991670993. The next prime is 991671017. The reversal of 991671007 is 700176199.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 991671007 - 2¹⁵ = 991638239 is a prime.

It is a super-2 number, since 2×991671007² = 1966822772248788098, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (991671017) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495835503 + 495835504.

It is an arithmetic number, because the mean of its divisors is an integer number (495835504).

Almost surely, 2^991671007 is an apocalyptic number.

991671007 is a deficient number, since it is larger than the sum of its proper divisors (1).

991671007 is an equidigital number, since it uses as much as digits as its factorization.

991671007 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23814, while the sum is 40.

The square root of 991671007 is about 31490.8082938498. The cubic root of 991671007 is about 997.2159251203.

The spelling of 991671007 in words is "nine hundred ninety-one million, six hundred seventy-one thousand, seven".