81520051041 has 48 divisors (see below), whose sum is σ = 138957891072. Its totient is φ = 45400953600.

The previous prime is 81520051031. The next prime is 81520051087. The reversal of 81520051041 is 14015002518.

It is not a de Polignac number, because 81520051041 - 2¹¹ = 81520048993 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81520050996 and 81520051014.

It is not an unprimeable number, because it can be changed into a prime (81520051021) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 144981 + ... + 429021.

It is an arithmetic number, because the mean of its divisors is an integer number (2894956064).

Almost surely, 2^81520051041 is an apocalyptic number.

It is an amenable number.

81520051041 is a deficient number, since it is larger than the sum of its proper divisors (57437840031).

81520051041 is a wasteful number, since it uses less digits than its factorization.

81520051041 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 284294 (or 284291 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 27.

Adding to 81520051041 its reverse (14015002518), we get a palindrome (95535053559).

The spelling of 81520051041 in words is "eighty-one billion, five hundred twenty million, fifty-one thousand, forty-one".