70782721 has 2 divisors, whose sum is σ = 70782722. Its totient is φ = 70782720.

The previous prime is 70782709. The next prime is 70782727. The reversal of 70782721 is 12728707.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 47114496 + 23668225 = 6864^2 + 4865^2 .

It is an emirp because it is prime and its reverse (12728707) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 70782721 - 2¹⁵ = 70749953 is a prime.

It is not a weakly prime, because it can be changed into another prime (70782727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35391360 + 35391361.

It is an arithmetic number, because the mean of its divisors is an integer number (35391361).

Almost surely, 2^70782721 is an apocalyptic number.

It is an amenable number.

70782721 is a deficient number, since it is larger than the sum of its proper divisors (1).

70782721 is an equidigital number, since it uses as much as digits as its factorization.

70782721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10976, while the sum is 34.

The square root of 70782721 is about 8413.2467573464. The cubic root of 70782721 is about 413.6589429749.

The spelling of 70782721 in words is "seventy million, seven hundred eighty-two thousand, seven hundred twenty-one".