11777800121 has 4 divisors (see below), whose sum is σ = 11790159732. Its totient is φ = 11765440512.

The previous prime is 11777800063. The next prime is 11777800127. The reversal of 11777800121 is 12100877711.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12100877711 = 13 ⋅930836747.

It can be written as a sum of positive squares in 2 ways, for example, as 1735555600 + 10042244521 = 41660^2 + 100211^2 .

It is a cyclic number.

It is not a de Polignac number, because 11777800121 - 2⁶ = 11777800057 is a prime.

It is a super-2 number, since 2×11777800121² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11777800127) 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, 6178376 + ... + 6180281.

It is an arithmetic number, because the mean of its divisors is an integer number (2947539933).

Almost surely, 2^11777800121 is an apocalyptic number.

It is an amenable number.

11777800121 is a deficient number, since it is larger than the sum of its proper divisors (12359611).

11777800121 is an equidigital number, since it uses as much as digits as its factorization.

11777800121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12359610.

The product of its (nonzero) digits is 5488, while the sum is 35.

The spelling of 11777800121 in words is "eleven billion, seven hundred seventy-seven million, eight hundred thousand, one hundred twenty-one".