71290957721 has 4 divisors (see below), whose sum is σ = 71339096244. Its totient is φ = 71242819200.

The previous prime is 71290957709. The next prime is 71290957739. The reversal of 71290957721 is 12775909217.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12775909217 = 379 ⋅33709523.

It can be written as a sum of positive squares in 2 ways, for example, as 32810250496 + 38480707225 = 181136^2 + 196165^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-71290957721 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 71290957721.

It is not an unprimeable number, because it can be changed into a prime (71290957741) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24067040 + ... + 24070001.

It is an arithmetic number, because the mean of its divisors is an integer number (17834774061).

Almost surely, 2^71290957721 is an apocalyptic number.

It is an amenable number.

71290957721 is a deficient number, since it is larger than the sum of its proper divisors (48138523).

71290957721 is a wasteful number, since it uses less digits than its factorization.

71290957721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48138522.

The product of its (nonzero) digits is 555660, while the sum is 50.

The spelling of 71290957721 in words is "seventy-one billion, two hundred ninety million, nine hundred fifty-seven thousand, seven hundred twenty-one".