65481638545 has 4 divisors (see below), whose sum is σ = 78577966260. Its totient is φ = 52385310832.

The previous prime is 65481638527. The next prime is 65481638561. The reversal of 65481638545 is 54583618456.

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 15336097921 + 50145540624 = 123839^2 + 223932^2 .

It is a cyclic number.

It is not a de Polignac number, because 65481638545 - 2²⁵ = 65448084113 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6548163850 + ... + 6548163859.

It is an arithmetic number, because the mean of its divisors is an integer number (19644491565).

Almost surely, 2^65481638545 is an apocalyptic number.

It is an amenable number.

65481638545 is a deficient number, since it is larger than the sum of its proper divisors (13096327715).

65481638545 is a wasteful number, since it uses less digits than its factorization.

65481638545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13096327714.

The product of its digits is 13824000, while the sum is 55.

The spelling of 65481638545 in words is "sixty-five billion, four hundred eighty-one million, six hundred thirty-eight thousand, five hundred forty-five".