4221656121 has 16 divisors (see below), whose sum is σ = 6165504000. Its totient is φ = 2557540608.

The previous prime is 4221656111. The next prime is 4221656191. The reversal of 4221656121 is 1216561224.

It is not a de Polignac number, because 4221656121 - 2⁶ = 4221656057 is a prime.

It is not an unprimeable number, because it can be changed into a prime (4221656111) 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, 1425721 + ... + 1428678.

It is an arithmetic number, because the mean of its divisors is an integer number (385344000).

Almost surely, 2^4221656121 is an apocalyptic number.

It is an amenable number.

4221656121 is a deficient number, since it is larger than the sum of its proper divisors (1943847879).

4221656121 is a wasteful number, since it uses less digits than its factorization.

4221656121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2854448.

The product of its digits is 5760, while the sum is 30.

The square root of 4221656121 is about 64974.2727623788. The cubic root of 4221656121 is about 1616.1969574224.

The spelling of 4221656121 in words is "four billion, two hundred twenty-one million, six hundred fifty-six thousand, one hundred twenty-one".