70721065 has 4 divisors (see below), whose sum is σ = 84865284. Its totient is φ = 56576848.

The previous prime is 70721047. The next prime is 70721069. The reversal of 70721065 is 56012707.

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

It can be written as a sum of positive squares in 2 ways, for example, as 20820969 + 49900096 = 4563^2 + 7064^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-70721065 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (70721069) 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, 7072102 + ... + 7072111.

It is an arithmetic number, because the mean of its divisors is an integer number (21216321).

Almost surely, 2^70721065 is an apocalyptic number.

It is an amenable number.

70721065 is a deficient number, since it is larger than the sum of its proper divisors (14144219).

70721065 is a wasteful number, since it uses less digits than its factorization.

70721065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14144218.

The product of its (nonzero) digits is 2940, while the sum is 28.

The square root of 70721065 is about 8409.5817375182. The cubic root of 70721065 is about 413.5388008256.

The spelling of 70721065 in words is "seventy million, seven hundred twenty-one thousand, sixty-five".