1678921415824 has 15 divisors (see below), whose sum is σ = 3252920285113. Its totient is φ = 839458116448.

The previous prime is 1678921415807. The next prime is 1678921415867. The reversal of 1678921415824 is 4285141298761.

It is a happy number.

The square root of 1678921415824 is 1295732.

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., 709941056400 + 968980359424 = 842580^2 + 984368^2 .

It is a super-3 number, since 3×1678921415824³ (a number of 38 digits) contains 333 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 5020962 + ... + 5344894.

Almost surely, 2^{1678921415824} is an apocalyptic number.

1678921415824 is the 1295732-nd square number.

It is an amenable number.

1678921415824 is a deficient number, since it is larger than the sum of its proper divisors (1573998869289).

1678921415824 is an frugal number, since it uses more digits than its factorization.

1678921415824 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 647874 (or 323935 counting only the distinct ones).

The product of its digits is 7741440, while the sum is 58.

The spelling of 1678921415824 in words is "one trillion, six hundred seventy-eight billion, nine hundred twenty-one million, four hundred fifteen thousand, eight hundred twenty-four".