51440101561 has 4 divisors (see below), whose sum is σ = 51832774224. Its totient is φ = 51047428900.

The previous prime is 51440101529. The next prime is 51440101571. The reversal of 51440101561 is 16510104415.

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 51440101561 - 2⁵ = 51440101529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51440101501) by changing a digit.

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, 196336135 + ... + 196336396.

It is an arithmetic number, because the mean of its divisors is an integer number (12958193556).

Almost surely, 2^51440101561 is an apocalyptic number.

It is an amenable number.

51440101561 is a deficient number, since it is larger than the sum of its proper divisors (392672663).

51440101561 is a wasteful number, since it uses less digits than its factorization.

51440101561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 392672662.

The product of its (nonzero) digits is 2400, while the sum is 28.

Adding to 51440101561 its reverse (16510104415), we get a palindrome (67950205976).

The spelling of 51440101561 in words is "fifty-one billion, four hundred forty million, one hundred one thousand, five hundred sixty-one".