39520564807681 has 4 divisors (see below), whose sum is σ = 39520758133764. Its totient is φ = 39520371481600.

The previous prime is 39520564807663. The next prime is 39520564807741. The reversal of 39520564807681 is 18670846502593.

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 2678590489600 + 36841974318081 = 1636640^2 + 6069759^2 .

It is a cyclic number.

It is not a de Polignac number, because 39520564807681 - 2¹⁷ = 39520564676609 is a prime.

It is a super-2 number, since 2×39520564807681² (a number of 28 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (39520564807601) 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, 96356080 + ... + 96765361.

It is an arithmetic number, because the mean of its divisors is an integer number (9880189533441).

It is a 1-persistent number, because it is pandigital, but 2⋅39520564807681 = 79041129615362 is not.

Almost surely, 2^{39520564807681} is an apocalyptic number.

It is an amenable number.

39520564807681 is a deficient number, since it is larger than the sum of its proper divisors (193326083).

39520564807681 is a wasteful number, since it uses less digits than its factorization.

39520564807681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 193326082.

The product of its (nonzero) digits is 87091200, while the sum is 64.

The spelling of 39520564807681 in words is "thirty-nine trillion, five hundred twenty billion, five hundred sixty-four million, eight hundred seven thousand, six hundred eighty-one".