51091390905 has 32 divisors (see below), whose sum is σ = 82923160320. Its totient is φ = 26856668160.

The previous prime is 51091390901. The next prime is 51091390919. The reversal of 51091390905 is 50909319015.

51091390905 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 51091390905 - 2² = 51091390901 is a prime.

It is a super-2 number, since 2×51091390905² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (51091390901) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5099541 + ... + 5109549.

It is an arithmetic number, because the mean of its divisors is an integer number (2591348760).

Almost surely, 2^51091390905 is an apocalyptic number.

It is an amenable number.

51091390905 is a deficient number, since it is larger than the sum of its proper divisors (31831769415).

51091390905 is a wasteful number, since it uses less digits than its factorization.

51091390905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14881.

The product of its (nonzero) digits is 54675, while the sum is 42.

The spelling of 51091390905 in words is "fifty-one billion, ninety-one million, three hundred ninety thousand, nine hundred five".