71642605541 has 4 divisors (see below), whose sum is σ = 77153575212. Its totient is φ = 66131635872.

The previous prime is 71642605519. The next prime is 71642605561. The reversal of 71642605541 is 14550624617.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 14550624617 = 43 ⋅338386619.

It can be written as a sum of positive squares in 2 ways, for example, as 14335033441 + 57307572100 = 119729^2 + 239390^2 .

It is a cyclic number.

It is not a de Polignac number, because 71642605541 - 2¹⁴ = 71642589157 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71642605561) 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, 2755484816 + ... + 2755484841.

It is an arithmetic number, because the mean of its divisors is an integer number (19288393803).

Almost surely, 2^71642605541 is an apocalyptic number.

It is an amenable number.

71642605541 is a deficient number, since it is larger than the sum of its proper divisors (5510969671).

71642605541 is a wasteful number, since it uses less digits than its factorization.

71642605541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5510969670.

The product of its (nonzero) digits is 201600, while the sum is 41.

The spelling of 71642605541 in words is "seventy-one billion, six hundred forty-two million, six hundred five thousand, five hundred forty-one".