4156661221 has 8 divisors (see below), whose sum is σ = 4266206784. Its totient is φ = 4047504480.

The previous prime is 4156661213. The next prime is 4156661231. The reversal of 4156661221 is 1221666514.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 4156661221 - 2³ = 4156661213 is a prime.

It is a super-4 number, since 4×4156661221⁴ (a number of 40 digits) contains 4444 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4156661231) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 75481 + ... + 118366.

It is an arithmetic number, because the mean of its divisors is an integer number (533275848).

Almost surely, 2^4156661221 is an apocalyptic number.

4156661221 is a gapful number since it is divisible by the number (41) formed by its first and last digit.

It is an amenable number.

4156661221 is a deficient number, since it is larger than the sum of its proper divisors (109545563).

4156661221 is a wasteful number, since it uses less digits than its factorization.

4156661221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 194411.

The product of its digits is 17280, while the sum is 34.

The square root of 4156661221 is about 64472.1740055351. The cubic root of 4156661221 is about 1607.8599217772.

The spelling of 4156661221 in words is "four billion, one hundred fifty-six million, six hundred sixty-one thousand, two hundred twenty-one".