1780788045221 has 4 divisors (see below), whose sum is σ = 1782138151200. Its totient is φ = 1779437939244.

The previous prime is 1780788045217. The next prime is 1780788045227. The reversal of 1780788045221 is 1225408870871.

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 not a de Polignac number, because 1780788045221 - 2² = 1780788045217 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1780788045227) 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, 675051011 + ... + 675053648.

It is an arithmetic number, because the mean of its divisors is an integer number (445534537800).

Almost surely, 2^{1780788045221} is an apocalyptic number.

It is an amenable number.

1780788045221 is a deficient number, since it is larger than the sum of its proper divisors (1350105979).

1780788045221 is a wasteful number, since it uses less digits than its factorization.

1780788045221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1350105978.

The product of its (nonzero) digits is 2007040, while the sum is 53.

The spelling of 1780788045221 in words is "one trillion, seven hundred eighty billion, seven hundred eighty-eight million, forty-five thousand, two hundred twenty-one".