49978531861 has 4 divisors (see below), whose sum is σ = 50063674752. Its totient is φ = 49893388972.

The previous prime is 49978531843. The next prime is 49978531919. The reversal of 49978531861 is 16813587994.

49978531861 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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.

It is a cyclic number.

It is not a de Polignac number, because 49978531861 - 2⁹ = 49978531349 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 49978531861.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (49978534861) 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, 42570565 + ... + 42571738.

It is an arithmetic number, because the mean of its divisors is an integer number (12515918688).

Almost surely, 2^49978531861 is an apocalyptic number.

It is an amenable number.

49978531861 is a deficient number, since it is larger than the sum of its proper divisors (85142891).

49978531861 is an equidigital number, since it uses as much as digits as its factorization.

49978531861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85142890.

The product of its digits is 13063680, while the sum is 61.

The spelling of 49978531861 in words is "forty-nine billion, nine hundred seventy-eight million, five hundred thirty-one thousand, eight hundred sixty-one".