72543517551161 has 4 divisors (see below), whose sum is σ = 72642485515812. Its totient is φ = 72444549586512.

The previous prime is 72543517551139. The next prime is 72543517551163. The reversal of 72543517551161 is 16115571534527.

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 40328596230400 + 32214921320761 = 6350480^2 + 5675819^2 .

It is a cyclic number.

It is not a de Polignac number, because 72543517551161 - 2²² = 72543513356857 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (72543517551163) 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, 49483981226 + ... + 49483982691.

It is an arithmetic number, because the mean of its divisors is an integer number (18160621378953).

Almost surely, 2^{72543517551161} is an apocalyptic number.

It is an amenable number.

72543517551161 is a deficient number, since it is larger than the sum of its proper divisors (98967964651).

72543517551161 is an equidigital number, since it uses as much as digits as its factorization.

72543517551161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98967964650.

The product of its digits is 4410000, while the sum is 53.

The spelling of 72543517551161 in words is "seventy-two trillion, five hundred forty-three billion, five hundred seventeen million, five hundred fifty-one thousand, one hundred sixty-one".