39721207687 has 6 divisors (see below), whose sum is σ = 45396268568. Its totient is φ = 34046297472.

The previous prime is 39721207639. The next prime is 39721207723. The reversal of 39721207687 is 78670212793.

It is a de Polignac number, because none of the positive numbers 2^k-39721207687 is a prime.

It is a super-2 number, since 2×39721207687² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (39721207607) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 489639 + ... + 564967.

Almost surely, 2^39721207687 is an apocalyptic number.

39721207687 is a deficient number, since it is larger than the sum of its proper divisors (5675060881).

39721207687 is an frugal number, since it uses more digits than its factorization.

39721207687 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150665 (or 75336 counting only the distinct ones).

The product of its (nonzero) digits is 1778112, while the sum is 52.

The spelling of 39721207687 in words is "thirty-nine billion, seven hundred twenty-one million, two hundred seven thousand, six hundred eighty-seven".