43217421 has 16 divisors (see below), whose sum is σ = 62758080. Its totient is φ = 26294400.

The previous prime is 43217413. The next prime is 43217423. The reversal of 43217421 is 12471234.

It is a happy number.

It is not a de Polignac number, because 43217421 - 2³ = 43217413 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 43217391 and 43217400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (43217423) 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, 2755 + ... + 9696.

It is an arithmetic number, because the mean of its divisors is an integer number (3922380).

Almost surely, 2^43217421 is an apocalyptic number.

It is an amenable number.

43217421 is a deficient number, since it is larger than the sum of its proper divisors (19540659).

43217421 is a wasteful number, since it uses less digits than its factorization.

43217421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12556.

The product of its digits is 1344, while the sum is 24.

The square root of 43217421 is about 6573.9958168529. The cubic root of 43217421 is about 350.9292882774.

Adding to 43217421 its reverse (12471234), we get a palindrome (55688655).

The spelling of 43217421 in words is "forty-three million, two hundred seventeen thousand, four hundred twenty-one".