43749631204121 has 4 divisors (see below), whose sum is σ = 43751610041700. Its totient is φ = 43747652366544.

The previous prime is 43749631204117. The next prime is 43749631204127. The reversal of 43749631204121 is 12140213694734.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 28151396912521 + 15598234291600 = 5305789^2 + 3949460^2 .

It is a cyclic number.

It is not a de Polignac number, because 43749631204121 - 2² = 43749631204117 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (43749631204127) 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, 989385626 + ... + 989429843.

It is an arithmetic number, because the mean of its divisors is an integer number (10937902510425).

Almost surely, 2^{43749631204121} is an apocalyptic number.

It is an amenable number.

43749631204121 is a deficient number, since it is larger than the sum of its proper divisors (1978837579).

43749631204121 is a wasteful number, since it uses less digits than its factorization.

43749631204121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1978837578.

The product of its (nonzero) digits is 870912, while the sum is 47.

Adding to 43749631204121 its reverse (12140213694734), we get a palindrome (55889844898855).

The spelling of 43749631204121 in words is "forty-three trillion, seven hundred forty-nine billion, six hundred thirty-one million, two hundred four thousand, one hundred twenty-one".