121993656761 has 4 divisors (see below), whose sum is σ = 122027425572. Its totient is φ = 121959887952.

The previous prime is 121993656739. The next prime is 121993656817. The reversal of 121993656761 is 167656399121.

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 41893902400 + 80099754361 = 204680^2 + 283019^2 .

It is a cyclic number.

It is not a de Polignac number, because 121993656761 - 2²² = 121989462457 is a prime.

It is a super-2 number, since 2×121993656761² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121993656697 and 121993656706.

It is not an unprimeable number, because it can be changed into a prime (121993656721) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16878986 + ... + 16886211.

It is an arithmetic number, because the mean of its divisors is an integer number (30506856393).

Almost surely, 2^121993656761 is an apocalyptic number.

It is an amenable number.

121993656761 is a deficient number, since it is larger than the sum of its proper divisors (33768811).

121993656761 is an equidigital number, since it uses as much as digits as its factorization.

121993656761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33768810.

The product of its digits is 3674160, while the sum is 56.

The spelling of 121993656761 in words is "one hundred twenty-one billion, nine hundred ninety-three million, six hundred fifty-six thousand, seven hundred sixty-one".