70016521 has 4 divisors (see below), whose sum is σ = 70322500. Its totient is φ = 69710544.

The previous prime is 70016519. The next prime is 70016537. The reversal of 70016521 is 12561007.

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 66194496 + 3822025 = 8136^2 + 1955^2 .

It is a cyclic number.

It is not a de Polignac number, because 70016521 - 2¹ = 70016519 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 70016492 and 70016501.

It is not an unprimeable number, because it can be changed into a prime (70013521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 152646 + ... + 153103.

It is an arithmetic number, because the mean of its divisors is an integer number (17580625).

Almost surely, 2^70016521 is an apocalyptic number.

It is an amenable number.

70016521 is a deficient number, since it is larger than the sum of its proper divisors (305979).

70016521 is a wasteful number, since it uses less digits than its factorization.

70016521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 305978.

The product of its (nonzero) digits is 420, while the sum is 22.

The square root of 70016521 is about 8367.5875256850. The cubic root of 70016521 is about 412.1609501707.

Adding to 70016521 its reverse (12561007), we get a palindrome (82577528).

The spelling of 70016521 in words is "seventy million, sixteen thousand, five hundred twenty-one".