70000991 has 2 divisors, whose sum is σ = 70000992. Its totient is φ = 70000990.

The previous prime is 70000943. The next prime is 70001011. The reversal of 70000991 is 19900007.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 70000991 - 2¹⁸ = 69738847 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 70000991.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (70000591) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35000495 + 35000496.

It is an arithmetic number, because the mean of its divisors is an integer number (35000496).

Almost surely, 2^70000991 is an apocalyptic number.

70000991 is a deficient number, since it is larger than the sum of its proper divisors (1).

70000991 is an equidigital number, since it uses as much as digits as its factorization.

70000991 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 26.

The square root of 70000991 is about 8366.6594887087. The cubic root of 70000991 is about 412.1304748258.

Adding to 70000991 its reverse (19900007), we get a palindrome (89900998).

The spelling of 70000991 in words is "seventy million, nine hundred ninety-one", and thus it is an aban number.