43406421 has 8 divisors (see below), whose sum is σ = 57907584. Its totient is φ = 28921440.

The previous prime is 43406399. The next prime is 43406437. The reversal of 43406421 is 12460434.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 43406421 - 2⁶ = 43406357 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 43406391 and 43406400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (43406021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5305 + ... + 10721.

It is an arithmetic number, because the mean of its divisors is an integer number (7238448).

Almost surely, 2^43406421 is an apocalyptic number.

It is an amenable number.

43406421 is a deficient number, since it is larger than the sum of its proper divisors (14501163).

43406421 is a wasteful number, since it uses less digits than its factorization.

43406421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8091.

The product of its (nonzero) digits is 2304, while the sum is 24.

The square root of 43406421 is about 6588.3549540079. The cubic root of 43406421 is about 351.4401099344.

Adding to 43406421 its reverse (12460434), we get a palindrome (55866855).

The spelling of 43406421 in words is "forty-three million, four hundred six thousand, four hundred twenty-one".