39781256545 has 4 divisors (see below), whose sum is σ = 47737507860. Its totient is φ = 31825005232.

The previous prime is 39781256507. The next prime is 39781256687. The reversal of 39781256545 is 54565218793.

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 18465548544 + 21315708001 = 135888^2 + 145999^2 .

It is a cyclic number.

It is not a de Polignac number, because 39781256545 - 2¹¹ = 39781254497 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3978125650 + ... + 3978125659.

It is an arithmetic number, because the mean of its divisors is an integer number (11934376965).

Almost surely, 2^39781256545 is an apocalyptic number.

It is an amenable number.

39781256545 is a deficient number, since it is larger than the sum of its proper divisors (7956251315).

39781256545 is an equidigital number, since it uses as much as digits as its factorization.

39781256545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7956251314.

The product of its digits is 9072000, while the sum is 55.

The spelling of 39781256545 in words is "thirty-nine billion, seven hundred eighty-one million, two hundred fifty-six thousand, five hundred forty-five".