71840616961 has 9 divisors (see below), whose sum is σ = 72535249731. Its totient is φ = 71152581384.

The previous prime is 71840616943. The next prime is 71840616973. The reversal of 71840616961 is 16961604817.

The square root of 71840616961 is 268031.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 50072565361 + 21768051600 = 223769^2 + 147540^2 .

It is not a de Polignac number, because 71840616961 - 2¹¹ = 71840614913 is a prime.

It is a super-2 number, since 2×71840616961² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71840613961) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 29214150 + ... + 29216608.

Almost surely, 2^71840616961 is an apocalyptic number.

71840616961 is the 268031-st square number.

71840616961 is the 134016-th centered octagonal number.

It is an amenable number.

71840616961 is a deficient number, since it is larger than the sum of its proper divisors (694632770).

71840616961 is an frugal number, since it uses more digits than its factorization.

71840616961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5136 (or 2568 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 49.

Multiplying 71840616961 by its sum of digits (49), we get a square (3520190231089 = 1876217²).

The spelling of 71840616961 in words is "seventy-one billion, eight hundred forty million, six hundred sixteen thousand, nine hundred sixty-one".