51978604381 has 4 divisors (see below), whose sum is σ = 56703932064. Its totient is φ = 47253276700.

The previous prime is 51978604367. The next prime is 51978604417. The reversal of 51978604381 is 18340687915.

51978604381 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 51978604381 - 2⁷ = 51978604253 is a prime.

It is a super-2 number, since 2×51978604381² (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 (51978604081) 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, 2362663825 + ... + 2362663846.

It is an arithmetic number, because the mean of its divisors is an integer number (14175983016).

Almost surely, 2^51978604381 is an apocalyptic number.

It is an amenable number.

51978604381 is a deficient number, since it is larger than the sum of its proper divisors (4725327683).

51978604381 is a wasteful number, since it uses less digits than its factorization.

51978604381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4725327682.

The product of its (nonzero) digits is 1451520, while the sum is 52.

The spelling of 51978604381 in words is "fifty-one billion, nine hundred seventy-eight million, six hundred four thousand, three hundred eighty-one".