39642991605 has 96 divisors (see below), whose sum is σ = 80254137600. Its totient is φ = 18095253120.

The previous prime is 39642991603. The next prime is 39642991607. The reversal of 39642991605 is 50619924693.

39642991605 is a `hidden beast` number, since 3 + 9 + 6 + 4 + 29 + 9 + 1 + 605 = 666.

It is an interprime number because it is at equal distance from previous prime (39642991603) and next prime (39642991607).

It is not a de Polignac number, because 39642991605 - 2¹ = 39642991603 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (39642991603) 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 95 ways as a sum of consecutive naturals, for example, 13164550 + ... + 13167560.

It is an arithmetic number, because the mean of its divisors is an integer number (835980600).

Almost surely, 2^39642991605 is an apocalyptic number.

39642991605 is a gapful number since it is divisible by the number (35) formed by its first and last digit.

It is an amenable number.

39642991605 is an abundant number, since it is smaller than the sum of its proper divisors (40611145995).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

39642991605 is a wasteful number, since it uses less digits than its factorization.

39642991605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3896 (or 3879 counting only the distinct ones).

The product of its (nonzero) digits is 3149280, while the sum is 54.

The spelling of 39642991605 in words is "thirty-nine billion, six hundred forty-two million, nine hundred ninety-one thousand, six hundred five".