2758778812261 has 4 divisors (see below), whose sum is σ = 2758835613024. Its totient is φ = 2758722011500.

The previous prime is 2758778812253. The next prime is 2758778812289. The reversal of 2758778812261 is 1622188778572.

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 2758778812261 - 2³ = 2758778812253 is a prime.

It is a super-2 number, since 2×2758778812261² (a number of 26 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 = 2758778812193 and 2758778812202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2758778812291) 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, 28327465 + ... + 28424686.

It is an arithmetic number, because the mean of its divisors is an integer number (689708903256).

Almost surely, 2^{2758778812261} is an apocalyptic number.

It is an amenable number.

2758778812261 is a deficient number, since it is larger than the sum of its proper divisors (56800763).

2758778812261 is an equidigital number, since it uses as much as digits as its factorization.

2758778812261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56800762.

The product of its digits is 42147840, while the sum is 64.

The spelling of 2758778812261 in words is "two trillion, seven hundred fifty-eight billion, seven hundred seventy-eight million, eight hundred twelve thousand, two hundred sixty-one".