4219721 has 4 divisors (see below), whose sum is σ = 4603344. Its totient is φ = 3836100.

The previous prime is 4219711. The next prime is 4219753. The reversal of 4219721 is 1279124.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-4219721 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (4219711) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 191795 + ... + 191816.

It is an arithmetic number, because the mean of its divisors is an integer number (1150836).

Almost surely, 2^4219721 is an apocalyptic number.

It is an amenable number.

4219721 is a deficient number, since it is larger than the sum of its proper divisors (383623).

4219721 is a wasteful number, since it uses less digits than its factorization.

4219721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 383622.

The product of its digits is 1008, while the sum is 26.

The square root of 4219721 is about 2054.1959497575. The cubic root of 4219721 is about 161.5949975782.

The spelling of 4219721 in words is "four million, two hundred nineteen thousand, seven hundred twenty-one".