43402421 has 2 divisors, whose sum is σ = 43402422. Its totient is φ = 43402420.

The previous prime is 43402397. The next prime is 43402433. The reversal of 43402421 is 12420434.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 42432196 + 970225 = 6514^2 + 985^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-43402421 is a prime.

It is a super-2 number, since 2×43402421² = 3767540297322482, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 43402393 and 43402402.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (43402451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21701210 + 21701211.

It is an arithmetic number, because the mean of its divisors is an integer number (21701211).

Almost surely, 2^43402421 is an apocalyptic number.

It is an amenable number.

43402421 is a deficient number, since it is larger than the sum of its proper divisors (1).

43402421 is an equidigital number, since it uses as much as digits as its factorization.

43402421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 768, while the sum is 20.

The square root of 43402421 is about 6588.0513810990. The cubic root of 43402421 is about 351.4293142687.

Adding to 43402421 its reverse (12420434), we get a palindrome (55822855).

The spelling of 43402421 in words is "forty-three million, four hundred two thousand, four hundred twenty-one".