51111010105561 has 12 divisors (see below), whose sum is σ = 60577469816292. Its totient is φ = 42982844075808.

The previous prime is 51111010105523. The next prime is 51111010105567. The reversal of 51111010105561 is 16550101011115.

It can be written as a sum of positive squares in 2 ways, for example, as 17219180160000 + 33891829945561 = 4149600^2 + 5821669^2 .

It is not a de Polignac number, because 51111010105561 - 2¹⁷ = 51111009974489 is a prime.

It is a super-2 number, since 2×51111010105561² (a number of 28 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51111010105567) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9840392110 + ... + 9840397303.

It is an arithmetic number, because the mean of its divisors is an integer number (5048122484691).

Almost surely, 2^{51111010105561} is an apocalyptic number.

It is an amenable number.

51111010105561 is a deficient number, since it is larger than the sum of its proper divisors (9466459710731).

51111010105561 is a wasteful number, since it uses less digits than its factorization.

51111010105561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19680789480 (or 19680789473 counting only the distinct ones).

The product of its (nonzero) digits is 750, while the sum is 28.

Adding to 51111010105561 its reverse (16550101011115), we get a palindrome (67661111116676).

The spelling of 51111010105561 in words is "fifty-one trillion, one hundred eleven billion, ten million, one hundred five thousand, five hundred sixty-one".