70809021 has 6 divisors (see below), whose sum is σ = 102279710. Its totient is φ = 47206008.

The previous prime is 70809001. The next prime is 70809031. The reversal of 70809021 is 12090807.

It can be written as a sum of positive squares in only one way, i.e., 56475225 + 14333796 = 7515^2 + 3786^2 .

It is not a de Polignac number, because 70809021 - 2⁵ = 70808989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (70809001) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3933826 + ... + 3933843.

Almost surely, 2^70809021 is an apocalyptic number.

It is an amenable number.

70809021 is a deficient number, since it is larger than the sum of its proper divisors (31470689).

70809021 is a wasteful number, since it uses less digits than its factorization.

70809021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7867675 (or 7867672 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 27.

The square root of 70809021 is about 8414.8096235150. The cubic root of 70809021 is about 413.7101696156.

Adding to 70809021 its reverse (12090807), we get a palindrome (82899828).

The spelling of 70809021 in words is "seventy million, eight hundred nine thousand, twenty-one".