1779998915556 has 27 divisors (see below), whose sum is σ = 4499461938153. Its totient is φ = 593330303520.

The previous prime is 1779998915509. The next prime is 1779998915599. The reversal of 1779998915556 is 6555198999771.

The square root of 1779998915556 is 1334166.

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

It can be written as a sum of positive squares in only one way, i.e., 1086043273956 + 693955641600 = 1042134^2 + 833040^2 .

It is a super-2 number, since 2×1779998915556² (a number of 25 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 7893816 + ... + 8116176.

Almost surely, 2^{1779998915556} is an apocalyptic number.

1779998915556 is the 1334166-th square number.

It is an amenable number.

1779998915556 is an abundant number, since it is smaller than the sum of its proper divisors (2719463022597).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1779998915556 is an frugal number, since it uses more digits than its factorization.

1779998915556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 444732 (or 222366 counting only the distinct ones).

The product of its digits is 1928934000, while the sum is 81.

Multiplying 1779998915556 by its sum of digits (81), we get a square (144179912160036 = 12007494²).

The spelling of 1779998915556 in words is "one trillion, seven hundred seventy-nine billion, nine hundred ninety-eight million, nine hundred fifteen thousand, five hundred fifty-six".