51215531034665 has 4 divisors (see below), whose sum is σ = 61458637241604. Its totient is φ = 40972424827728.

The previous prime is 51215531034557. The next prime is 51215531034673. The reversal of 51215531034665 is 56643013551215.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7079345775616 + 44136185259049 = 2660704^2 + 6643507^2 .

It is a cyclic number.

It is not a de Polignac number, because 51215531034665 - 2¹² = 51215531030569 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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, 5121553103462 + ... + 5121553103471.

It is an arithmetic number, because the mean of its divisors is an integer number (15364659310401).

Almost surely, 2^{51215531034665} is an apocalyptic number.

It is an amenable number.

51215531034665 is a deficient number, since it is larger than the sum of its proper divisors (10243106206939).

51215531034665 is a wasteful number, since it uses less digits than its factorization.

51215531034665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10243106206938.

The product of its (nonzero) digits is 1620000, while the sum is 47.

The spelling of 51215531034665 in words is "fifty-one trillion, two hundred fifteen billion, five hundred thirty-one million, thirty-four thousand, six hundred sixty-five".