4021720 has 32 divisors (see below), whose sum is σ = 9363600. Its totient is φ = 1552768.

The previous prime is 4021663. The next prime is 4021727. The reversal of 4021720 is 271204.

4021720 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is an Ulam number.

It is a nialpdrome in base 13.

It is a junction number, because it is equal to n+sod(n) for n = 4021694 and 4021703.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4021727) 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, 574 + ... + 2893.

Almost surely, 2^4021720 is an apocalyptic number.

4021720 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

4021720 is an abundant number, since it is smaller than the sum of its proper divisors (5341880).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

4021720 is a wasteful number, since it uses less digits than its factorization.

4021720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3507 (or 3503 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 16.

The square root of 4021720 is about 2005.4226487202. The cubic root of 4021720 is about 159.0269063019.

Adding to 4021720 its reverse (271204), we get a palindrome (4292924).

The spelling of 4021720 in words is "four million, twenty-one thousand, seven hundred twenty".