70978991 has 2 divisors, whose sum is σ = 70978992. Its totient is φ = 70978990.

The previous prime is 70978949. The next prime is 70978993. The reversal of 70978991 is 19987907.

It is a strong prime.

It is an emirp because it is prime and its reverse (19987907) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 70978991 - 2¹⁰ = 70977967 is a prime.

Together with 70978993, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (70978993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35489495 + 35489496.

It is an arithmetic number, because the mean of its divisors is an integer number (35489496).

Almost surely, 2^70978991 is an apocalyptic number.

70978991 is a deficient number, since it is larger than the sum of its proper divisors (1).

70978991 is an equidigital number, since it uses as much as digits as its factorization.

70978991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 285768, while the sum is 50.

The square root of 70978991 is about 8424.9030261481. The cubic root of 70978991 is about 414.0409284530.

The spelling of 70978991 in words is "seventy million, nine hundred seventy-eight thousand, nine hundred ninety-one".