126216221 has 16 divisors (see below), whose sum is σ = 137740800. Its totient is φ = 115214400.

The previous prime is 126216193. The next prime is 126216239. The reversal of 126216221 is 122612621.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 126216221 - 2²⁶ = 59107357 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 (126216241) 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, 247715 + ... + 248223.

It is an arithmetic number, because the mean of its divisors is an integer number (8608800).

Almost surely, 2^126216221 is an apocalyptic number.

It is an amenable number.

126216221 is a deficient number, since it is larger than the sum of its proper divisors (11524579).

126216221 is a wasteful number, since it uses less digits than its factorization.

126216221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 980.

The product of its digits is 576, while the sum is 23.

The square root of 126216221 is about 11234.5992807932. The cubic root of 126216221 is about 501.6163968912.

Adding to 126216221 its reverse (122612621), we get a palindrome (248828842).

The spelling of 126216221 in words is "one hundred twenty-six million, two hundred sixteen thousand, two hundred twenty-one".