70919809 has 4 divisors (see below), whose sum is σ = 71036116. Its totient is φ = 70803504.

The previous prime is 70919753. The next prime is 70919813. The reversal of 70919809 is 90891907.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90891907 = 31 ⋅2931997.

It can be written as a sum of positive squares in 2 ways, for example, as 107584 + 70812225 = 328^2 + 8415^2 .

It is a cyclic number.

It is not a de Polignac number, because 70919809 - 2¹⁵ = 70887041 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (70919839) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 57234 + ... + 58459.

It is an arithmetic number, because the mean of its divisors is an integer number (17759029).

Almost surely, 2^70919809 is an apocalyptic number.

It is an amenable number.

70919809 is a deficient number, since it is larger than the sum of its proper divisors (116307).

70919809 is a wasteful number, since it uses less digits than its factorization.

70919809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116306.

The product of its (nonzero) digits is 40824, while the sum is 43.

The square root of 70919809 is about 8421.3899684078. The cubic root of 70919809 is about 413.9258212294.

It can be divided in two parts, 7091 and 9809, that added together give a square (16900 = 130²).

The spelling of 70919809 in words is "seventy million, nine hundred nineteen thousand, eight hundred nine".