51081507487 has 4 divisors (see below), whose sum is σ = 51202841656. Its totient is φ = 50960173320.

The previous prime is 51081507473. The next prime is 51081507527. The reversal of 51081507487 is 78470518015.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 51081507487 - 2⁷ = 51081507359 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 (51081507427) 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, 60666453 + ... + 60667294.

It is an arithmetic number, because the mean of its divisors is an integer number (12800710414).

Almost surely, 2^51081507487 is an apocalyptic number.

51081507487 is a deficient number, since it is larger than the sum of its proper divisors (121334169).

51081507487 is a wasteful number, since it uses less digits than its factorization.

51081507487 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 121334168.

The product of its (nonzero) digits is 313600, while the sum is 46.

The spelling of 51081507487 in words is "fifty-one billion, eighty-one million, five hundred seven thousand, four hundred eighty-seven".