51354720491 has 4 divisors (see below), whose sum is σ = 51355893312. Its totient is φ = 51353547672.

The previous prime is 51354720467. The next prime is 51354720517. The reversal of 51354720491 is 19402745315.

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 51354720491 - 2⁶ = 51354720427 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51354720401) 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, 518075 + ... + 609188.

It is an arithmetic number, because the mean of its divisors is an integer number (12838973328).

Almost surely, 2^51354720491 is an apocalyptic number.

51354720491 is a deficient number, since it is larger than the sum of its proper divisors (1172821).

51354720491 is a wasteful number, since it uses less digits than its factorization.

51354720491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1172820.

The product of its (nonzero) digits is 151200, while the sum is 41.

The spelling of 51354720491 in words is "fifty-one billion, three hundred fifty-four million, seven hundred twenty thousand, four hundred ninety-one".