39688732561421 has 8 divisors (see below), whose sum is σ = 39777399692184. Its totient is φ = 39600076576320.

The previous prime is 39688732561417. The next prime is 39688732561453. The reversal of 39688732561421 is 12416523788693.

It can be written as a sum of positive squares in 4 ways, for example, as 1391373589225 + 38297358972196 = 1179565^2 + 6188486^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 39688732561421 - 2² = 39688732561417 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (39688732561481) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4363835 + ... + 9920711.

It is an arithmetic number, because the mean of its divisors is an integer number (4972174961523).

Almost surely, 2^{39688732561421} is an apocalyptic number.

It is an amenable number.

39688732561421 is a deficient number, since it is larger than the sum of its proper divisors (88667130763).

39688732561421 is a wasteful number, since it uses less digits than its factorization.

39688732561421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5572831.

The product of its digits is 104509440, while the sum is 65.

The spelling of 39688732561421 in words is "thirty-nine trillion, six hundred eighty-eight billion, seven hundred thirty-two million, five hundred sixty-one thousand, four hundred twenty-one".