42206621 has 2 divisors, whose sum is σ = 42206622. Its totient is φ = 42206620.

The previous prime is 42206599. The next prime is 42206627. The reversal of 42206621 is 12660224.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 22934521 + 19272100 = 4789^2 + 4390^2 .

It is a cyclic number.

It is not a de Polignac number, because 42206621 - 2¹⁸ = 41944477 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42206627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21103310 + 21103311.

It is an arithmetic number, because the mean of its divisors is an integer number (21103311).

Almost surely, 2^42206621 is an apocalyptic number.

It is an amenable number.

42206621 is a deficient number, since it is larger than the sum of its proper divisors (1).

42206621 is an equidigital number, since it uses as much as digits as its factorization.

42206621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 42206621 is about 6496.6622969029. The cubic root of 42206621 is about 348.1717482483.

Adding to 42206621 its reverse (12660224), we get a palindrome (54866845).

The spelling of 42206621 in words is "forty-two million, two hundred six thousand, six hundred twenty-one".