70521643 has 4 divisors (see below), whose sum is σ = 70538440. Its totient is φ = 70504848.

The previous prime is 70521637. The next prime is 70521679. The reversal of 70521643 is 34612507.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 34612507 = 79 ⋅438133.

It is a cyclic number.

It is not a de Polignac number, because 70521643 - 2⁹ = 70521131 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (70521043) 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, 4096 + ... + 12562.

It is an arithmetic number, because the mean of its divisors is an integer number (17634610).

Almost surely, 2^70521643 is an apocalyptic number.

70521643 is a deficient number, since it is larger than the sum of its proper divisors (16797).

70521643 is an equidigital number, since it uses as much as digits as its factorization.

70521643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16796.

The product of its (nonzero) digits is 5040, while the sum is 28.

The square root of 70521643 is about 8397.7165348683. The cubic root of 70521643 is about 413.1497306450.

The spelling of 70521643 in words is "seventy million, five hundred twenty-one thousand, six hundred forty-three".