70978891 has 4 divisors (see below), whose sum is σ = 71029000. Its totient is φ = 70928784.

The previous prime is 70978879. The next prime is 70978907. The reversal of 70978891 is 19887907.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 70978891 - 2⁷ = 70978763 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (70978801) 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 in 3 ways as a sum of consecutive naturals, for example, 22866 + ... + 25783.

It is an arithmetic number, because the mean of its divisors is an integer number (17757250).

Almost surely, 2^70978891 is an apocalyptic number.

70978891 is a deficient number, since it is larger than the sum of its proper divisors (50109).

70978891 is a wasteful number, since it uses less digits than its factorization.

70978891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50108.

The product of its (nonzero) digits is 254016, while the sum is 49.

The square root of 70978891 is about 8424.8970913596. The cubic root of 70978891 is about 414.0407340100.

The spelling of 70978891 in words is "seventy million, nine hundred seventy-eight thousand, eight hundred ninety-one".