2780605217761 has 4 divisors (see below), whose sum is σ = 3177834534592. Its totient is φ = 2383375900932.

The previous prime is 2780605217743. The next prime is 2780605217771. The reversal of 2780605217761 is 1677125060872.

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 2780605217761 - 2⁵ = 2780605217729 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2780605217699 and 2780605217708.

It is not an unprimeable number, because it can be changed into a prime (2780605217711) 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, 198614658405 + ... + 198614658418.

It is an arithmetic number, because the mean of its divisors is an integer number (794458633648).

Almost surely, 2^{2780605217761} is an apocalyptic number.

It is an amenable number.

2780605217761 is a deficient number, since it is larger than the sum of its proper divisors (397229316831).

2780605217761 is an equidigital number, since it uses as much as digits as its factorization.

2780605217761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 397229316830.

The product of its (nonzero) digits is 1975680, while the sum is 52.

The spelling of 2780605217761 in words is "two trillion, seven hundred eighty billion, six hundred five million, two hundred seventeen thousand, seven hundred sixty-one".