3928920207557 has 4 divisors (see below), whose sum is σ = 3928950920556. Its totient is φ = 3928889494560.

The previous prime is 3928920207497. The next prime is 3928920207599. The reversal of 3928920207557 is 7557020298293.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2273101997761 + 1655818209796 = 1507681^2 + 1286786^2 .

It is a cyclic number.

It is not a de Polignac number, because 3928920207557 - 2⁶ = 3928920207493 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 3928920207496 and 3928920207505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3928920207757) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15163808 + ... + 15420729.

It is an arithmetic number, because the mean of its divisors is an integer number (982237730139).

Almost surely, 2^{3928920207557} is an apocalyptic number.

It is an amenable number.

3928920207557 is a deficient number, since it is larger than the sum of its proper divisors (30712999).

3928920207557 is a wasteful number, since it uses less digits than its factorization.

3928920207557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30712998.

The product of its (nonzero) digits is 19051200, while the sum is 59.

The spelling of 3928920207557 in words is "three trillion, nine hundred twenty-eight billion, nine hundred twenty million, two hundred seven thousand, five hundred fifty-seven".