43401138721 has 16 divisors (see below), whose sum is σ = 46147354560. Its totient is φ = 40815861408.

The previous prime is 43401138707. The next prime is 43401138727. The reversal of 43401138721 is 12783110434.

It is not a de Polignac number, because 43401138721 - 2⁷ = 43401138593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (43401138727) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 916590 + ... + 962776.

It is an arithmetic number, because the mean of its divisors is an integer number (2884209660).

Almost surely, 2^43401138721 is an apocalyptic number.

It is an amenable number.

43401138721 is a deficient number, since it is larger than the sum of its proper divisors (2746215839).

43401138721 is an equidigital number, since it uses as much as digits as its factorization.

43401138721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46381 (or 46343 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 34.

The spelling of 43401138721 in words is "forty-three billion, four hundred one million, one hundred thirty-eight thousand, seven hundred twenty-one".