43263421921 has 4 divisors (see below), whose sum is σ = 43292055744. Its totient is φ = 43234788100.

The previous prime is 43263421897. The next prime is 43263421939. The reversal of 43263421921 is 12912436234.

43263421921 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, and also an emirpimes, since its reverse is a distinct semiprime: 12912436234 = 2 ⋅6456218117.

It is a cyclic number.

It is not a de Polignac number, because 43263421921 - 2³⁵ = 8903683553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (43263421951) 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, 14314645 + ... + 14317666.

It is an arithmetic number, because the mean of its divisors is an integer number (10823013936).

Almost surely, 2^43263421921 is an apocalyptic number.

It is an amenable number.

43263421921 is a deficient number, since it is larger than the sum of its proper divisors (28633823).

43263421921 is a wasteful number, since it uses less digits than its factorization.

43263421921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28633822.

The product of its digits is 62208, while the sum is 37.

The spelling of 43263421921 in words is "forty-three billion, two hundred sixty-three million, four hundred twenty-one thousand, nine hundred twenty-one".