70217281 has 4 divisors (see below), whose sum is σ = 70248532. Its totient is φ = 70186032.

The previous prime is 70217243. The next prime is 70217309. The reversal of 70217281 is 18271207.

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 40960000 + 29257281 = 6400^2 + 5409^2 .

It is a cyclic number.

It is not a de Polignac number, because 70217281 - 2¹⁷ = 70086209 is a prime.

It is a super-2 number, since 2×70217281² = 9860933102065922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (70217221) 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, 11970 + ... + 16843.

It is an arithmetic number, because the mean of its divisors is an integer number (17562133).

Almost surely, 2^70217281 is an apocalyptic number.

It is an amenable number.

70217281 is a deficient number, since it is larger than the sum of its proper divisors (31251).

70217281 is a wasteful number, since it uses less digits than its factorization.

70217281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31250.

The product of its (nonzero) digits is 1568, while the sum is 28.

The square root of 70217281 is about 8379.5752278979. The cubic root of 70217281 is about 412.5545071529.

Adding to 70217281 its reverse (18271207), we get a palindrome (88488488).

The spelling of 70217281 in words is "seventy million, two hundred seventeen thousand, two hundred eighty-one".