51318201381 has 32 divisors (see below), whose sum is σ = 73775923200. Its totient is φ = 31637443200.

The previous prime is 51318201377. The next prime is 51318201421. The reversal of 51318201381 is 18310281315.

It is not a de Polignac number, because 51318201381 - 2² = 51318201377 is a prime.

It is a super-2 number, since 2×51318201381² (a number of 22 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51314201381) 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, 2232376 + ... + 2255246.

It is an arithmetic number, because the mean of its divisors is an integer number (2305497600).

Almost surely, 2^51318201381 is an apocalyptic number.

It is an amenable number.

51318201381 is a deficient number, since it is larger than the sum of its proper divisors (22457721819).

51318201381 is a wasteful number, since it uses less digits than its factorization.

51318201381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23977.

The product of its (nonzero) digits is 5760, while the sum is 33.

Adding to 51318201381 its reverse (18310281315), we get a palindrome (69628482696).

The spelling of 51318201381 in words is "fifty-one billion, three hundred eighteen million, two hundred one thousand, three hundred eighty-one".