43131421 has 4 divisors (see below), whose sum is σ = 43152700. Its totient is φ = 43110144.

The previous prime is 43131391. The next prime is 43131433. The reversal of 43131421 is 12413134.

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 17264025 + 25867396 = 4155^2 + 5086^2 .

It is a cyclic number.

It is not a de Polignac number, because 43131421 - 2⁹ = 43130909 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (43131461) 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, 7236 + ... + 11773.

It is an arithmetic number, because the mean of its divisors is an integer number (10788175).

Almost surely, 2^43131421 is an apocalyptic number.

It is an amenable number.

43131421 is a deficient number, since it is larger than the sum of its proper divisors (21279).

43131421 is a wasteful number, since it uses less digits than its factorization.

43131421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21278.

The product of its digits is 288, while the sum is 19.

The square root of 43131421 is about 6567.4516366700. The cubic root of 43131421 is about 350.6963578296.

Adding to 43131421 its reverse (12413134), we get a palindrome (55544555).

The spelling of 43131421 in words is "forty-three million, one hundred thirty-one thousand, four hundred twenty-one".