1777840889449 has 3 divisors (see below), whose sum is σ = 1777842222807. Its totient is φ = 1777839556092.

The previous prime is 1777840889431. The next prime is 1777840889479. The reversal of 1777840889449 is 9449880487771.

The square root of 1777840889449 is 1333357.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 66667225 + 1777774222224 = 8165^2 + 1333332^2 .

It is a de Polignac number, because none of the positive numbers 2^k-1777840889449 is a prime.

It is a super-2 number, since 2×1777840889449² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1777840889479) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 666679 + ... + 2000035.

It is an arithmetic number, because the mean of its divisors is an integer number (592614074269).

Almost surely, 2^{1777840889449} is an apocalyptic number.

1777840889449 is the 1333357-th square number.

1777840889449 is the 666679-th centered octagonal number.

It is an amenable number.

1777840889449 is a deficient number, since it is larger than the sum of its proper divisors (1333358).

1777840889449 is an frugal number, since it uses more digits than its factorization.

1777840889449 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2666714 (or 1333357 counting only the distinct ones).

The product of its (nonzero) digits is 910393344, while the sum is 76.

The spelling of 1777840889449 in words is "one trillion, seven hundred seventy-seven billion, eight hundred forty million, eight hundred eighty-nine thousand, four hundred forty-nine".