51505601021661 has 8 divisors (see below), whose sum is σ = 68674175984320. Its totient is φ = 34337046703392.

The previous prime is 51505601021627. The next prime is 51505601021717. The reversal of 51505601021661 is 16612010650515.

51505601021661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 51505601021661 - 2⁷ = 51505601021533 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51505601061661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2132985 + ... + 10371153.

It is an arithmetic number, because the mean of its divisors is an integer number (8584271998040).

Almost surely, 2^{51505601021661} is an apocalyptic number.

It is an amenable number.

51505601021661 is a deficient number, since it is larger than the sum of its proper divisors (17168574962659).

51505601021661 is a wasteful number, since it uses less digits than its factorization.

51505601021661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10322195.

The product of its (nonzero) digits is 54000, while the sum is 39.

The spelling of 51505601021661 in words is "fifty-one trillion, five hundred five billion, six hundred one million, twenty-one thousand, six hundred sixty-one".