39997129849 has 4 divisors (see below), whose sum is σ = 39997607760. Its totient is φ = 39996651940.

The previous prime is 39997129841. The next prime is 39997129859. The reversal of 39997129849 is 94892179993.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 94892179993 = 13 ⋅7299398461.

It is a cyclic number.

It is not a de Polignac number, because 39997129849 - 2³ = 39997129841 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (39997129841) 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, 76687 + ... + 293044.

It is an arithmetic number, because the mean of its divisors is an integer number (9999401940).

Almost surely, 2^39997129849 is an apocalyptic number.

It is an amenable number.

39997129849 is a deficient number, since it is larger than the sum of its proper divisors (477911).

39997129849 is a wasteful number, since it uses less digits than its factorization.

39997129849 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 477910.

The product of its digits is 79361856, while the sum is 70.

The spelling of 39997129849 in words is "thirty-nine billion, nine hundred ninety-seven million, one hundred twenty-nine thousand, eight hundred forty-nine".