71016447821 has 4 divisors (see below), whose sum is σ = 77472488544. Its totient is φ = 64560407100.

The previous prime is 71016447787. The next prime is 71016447863. The reversal of 71016447821 is 12874461017.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12874461017 = 11 ⋅1170405547.

It is a cyclic number.

It is not a de Polignac number, because 71016447821 - 2⁶ = 71016447757 is a prime.

It is a super-2 number, since 2×71016447821² (a number of 23 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71016447871) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3228020345 + ... + 3228020366.

It is an arithmetic number, because the mean of its divisors is an integer number (19368122136).

Almost surely, 2^71016447821 is an apocalyptic number.

It is an amenable number.

71016447821 is a deficient number, since it is larger than the sum of its proper divisors (6456040723).

71016447821 is a wasteful number, since it uses less digits than its factorization.

71016447821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6456040722.

The product of its (nonzero) digits is 75264, while the sum is 41.

The spelling of 71016447821 in words is "seventy-one billion, sixteen million, four hundred forty-seven thousand, eight hundred twenty-one".