221945421 has 16 divisors (see below), whose sum is σ = 320004864. Its totient is φ = 136295424.

The previous prime is 221945417. The next prime is 221945443. The reversal of 221945421 is 124549122.

It is not a de Polignac number, because 221945421 - 2² = 221945417 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221945491) 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, 43900 + ... + 48693.

It is an arithmetic number, because the mean of its divisors is an integer number (20000304).

Almost surely, 2^221945421 is an apocalyptic number.

It is an amenable number.

221945421 is a deficient number, since it is larger than the sum of its proper divisors (98059443).

221945421 is a wasteful number, since it uses less digits than its factorization.

221945421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92660.

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

The square root of 221945421 is about 14897.8327618483. The cubic root of 221945421 is about 605.4552691852.

The spelling of 221945421 in words is "two hundred twenty-one million, nine hundred forty-five thousand, four hundred twenty-one".