71428649 has 4 divisors (see below), whose sum is σ = 71950164. Its totient is φ = 70907136.

The previous prime is 71428631. The next prime is 71428691. The reversal of 71428649 is 94682417.

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 45091225 + 26337424 = 6715^2 + 5132^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-71428649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71428699) 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, 260552 + ... + 260825.

It is an arithmetic number, because the mean of its divisors is an integer number (17987541).

Almost surely, 2^71428649 is an apocalyptic number.

It is an amenable number.

71428649 is a deficient number, since it is larger than the sum of its proper divisors (521515).

71428649 is a wasteful number, since it uses less digits than its factorization.

71428649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 521514.

The product of its digits is 96768, while the sum is 41.

The square root of 71428649 is about 8451.5471364715. The cubic root of 71428649 is about 414.9134168817.

The spelling of 71428649 in words is "seventy-one million, four hundred twenty-eight thousand, six hundred forty-nine".