51815464019 has 4 divisors (see below), whose sum is σ = 56525960760. Its totient is φ = 47104967280.

The previous prime is 51815463979. The next prime is 51815464027. The reversal of 51815464019 is 91046451815.

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 51815464019 - 2¹² = 51815459923 is a prime.

It is a super-2 number, since 2×51815464019² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51815464079) 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, 2355248354 + ... + 2355248375.

It is an arithmetic number, because the mean of its divisors is an integer number (14131490190).

Almost surely, 2^51815464019 is an apocalyptic number.

51815464019 is a deficient number, since it is larger than the sum of its proper divisors (4710496741).

51815464019 is a wasteful number, since it uses less digits than its factorization.

51815464019 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4710496740.

The product of its (nonzero) digits is 172800, while the sum is 44.

The spelling of 51815464019 in words is "fifty-one billion, eight hundred fifteen million, four hundred sixty-four thousand, nineteen".