51866618121 has 6 divisors (see below), whose sum is σ = 74918448410. Its totient is φ = 34577745408.

The previous prime is 51866618107. The next prime is 51866618137. The reversal of 51866618121 is 12181666815.

It can be written as a sum of positive squares in only one way, i.e., 37511942400 + 14354675721 = 193680^2 + 119811^2 .

It is not a de Polignac number, because 51866618121 - 2¹³ = 51866609929 is a prime.

It is a super-3 number, since 3×51866618121³ (a number of 33 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51866618101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2881478776 + ... + 2881478793.

Almost surely, 2^51866618121 is an apocalyptic number.

It is an amenable number.

51866618121 is a deficient number, since it is larger than the sum of its proper divisors (23051830289).

51866618121 is a wasteful number, since it uses less digits than its factorization.

51866618121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5762957575 (or 5762957572 counting only the distinct ones).

The product of its digits is 138240, while the sum is 45.

The spelling of 51866618121 in words is "fifty-one billion, eight hundred sixty-six million, six hundred eighteen thousand, one hundred twenty-one".