1928512686681 has 225 divisors, whose sum is σ = 3485852984229. Its totient is φ = 1062462372048.

The previous prime is 1928512686673. The next prime is 1928512686769. The reversal of 1928512686681 is 1866862158291.

The square root of 1928512686681 is 1388709.

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

1928512686681 is a `hidden beast` number, since 19 + 28 + 512 + 6 + 8 + 6 + 6 + 81 = 666.

It is not a de Polignac number, because 1928512686681 - 2³ = 1928512686673 is a prime.

It is a super-2 number, since 2×1928512686681² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (1928512685681) by changing a digit.

It is a polite number, since it can be written in 224 ways as a sum of consecutive naturals, for example, 28783771410 + ... + 28783771476.

Almost surely, 2^{1928512686681} is an apocalyptic number.

1928512686681 is the 1388709-th square number.

1928512686681 is the 694355-th centered octagonal number.

It is an amenable number.

1928512686681 is a deficient number, since it is larger than the sum of its proper divisors (1557340297548).

1928512686681 is an frugal number, since it uses more digits than its factorization.

1928512686681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 268 (or 124 counting only the distinct ones).

The product of its digits is 19906560, while the sum is 63.

The spelling of 1928512686681 in words is "one trillion, nine hundred twenty-eight billion, five hundred twelve million, six hundred eighty-six thousand, six hundred eighty-one".