3928280396121 has 27 divisors (see below), whose sum is σ = 5892362037471. Its totient is φ = 2618746570008.

The previous prime is 3928280396119. The next prime is 3928280396129. The reversal of 3928280396121 is 1216930828293.

The square root of 3928280396121 is 1981989.

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

3928280396121 is a `hidden beast` number, since 3 + 92 + 82 + 80 + 396 + 12 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 571250267721 + 3357030128400 = 755811^2 + 1832220^2 .

It is a tau number, because it is divible by the number of its divisors (27).

It is not a de Polignac number, because 3928280396121 - 2¹ = 3928280396119 is a prime.

It is not an unprimeable number, because it can be changed into a prime (3928280396129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 160528875 + ... + 160553343.

Almost surely, 2^{3928280396121} is an apocalyptic number.

3928280396121 is the 1981989-th square number.

3928280396121 is the 990995-th centered octagonal number.

It is an amenable number.

3928280396121 is a deficient number, since it is larger than the sum of its proper divisors (1964081641350).

3928280396121 is an frugal number, since it uses more digits than its factorization.

3928280396121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48962 (or 24472 counting only the distinct ones).

The product of its (nonzero) digits is 2239488, while the sum is 54.

The spelling of 3928280396121 in words is "three trillion, nine hundred twenty-eight billion, two hundred eighty million, three hundred ninety-six thousand, one hundred twenty-one".