51155012381 has 4 divisors (see below), whose sum is σ = 55805468064. Its totient is φ = 46504556700.

The previous prime is 51155012369. The next prime is 51155012401. The reversal of 51155012381 is 18321055115.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 51155012381 - 2¹⁸ = 51154750237 is a prime.

It is a super-2 number, since 2×51155012381² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51155011381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2325227825 + ... + 2325227846.

It is an arithmetic number, because the mean of its divisors is an integer number (13951367016).

Almost surely, 2^51155012381 is an apocalyptic number.

It is an amenable number.

51155012381 is a deficient number, since it is larger than the sum of its proper divisors (4650455683).

51155012381 is a wasteful number, since it uses less digits than its factorization.

51155012381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4650455682.

The product of its (nonzero) digits is 6000, while the sum is 32.

Adding to 51155012381 its reverse (18321055115), we get a palindrome (69476067496).

The spelling of 51155012381 in words is "fifty-one billion, one hundred fifty-five million, twelve thousand, three hundred eighty-one".