51387981844969 has 16 divisors (see below), whose sum is σ = 64068746587776. Its totient is φ = 40042199894400.

The previous prime is 51387981844949. The next prime is 51387981844981. The reversal of 51387981844969 is 96944818978315.

It is not a de Polignac number, because 51387981844969 - 2¹⁵ = 51387981812201 is a prime.

It is a super-2 number, since 2×51387981844969² (a number of 28 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 51387981844892 and 51387981844901.

It is not an unprimeable number, because it can be changed into a prime (51387981844949) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5037139 + ... + 11320279.

It is an arithmetic number, because the mean of its divisors is an integer number (4004296661736).

Almost surely, 2^{51387981844969} is an apocalyptic number.

It is an amenable number.

51387981844969 is a deficient number, since it is larger than the sum of its proper divisors (12680764742807).

51387981844969 is a wasteful number, since it uses less digits than its factorization.

51387981844969 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6389376.

The product of its digits is 3762339840, while the sum is 82.

The spelling of 51387981844969 in words is "fifty-one trillion, three hundred eighty-seven billion, nine hundred eighty-one million, eight hundred forty-four thousand, nine hundred sixty-nine".