3428721 has 12 divisors (see below), whose sum is σ = 5213520. Its totient is φ = 2165400.

The previous prime is 3428717. The next prime is 3428743. The reversal of 3428721 is 1278243.

It is not a de Polignac number, because 3428721 - 2² = 3428717 is a prime.

It is a super-2 number, since 2×3428721² = 23512255391682, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (3428021) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9855 + ... + 10196.

It is an arithmetic number, because the mean of its divisors is an integer number (434460).

Almost surely, 2^3428721 is an apocalyptic number.

It is an amenable number.

3428721 is a deficient number, since it is larger than the sum of its proper divisors (1784799).

3428721 is a wasteful number, since it uses less digits than its factorization.

3428721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20076 (or 20073 counting only the distinct ones).

The product of its digits is 2688, while the sum is 27.

The square root of 3428721 is about 1851.6805880065. The cubic root of 3428721 is about 150.7916809244.

It can be divided in two parts, 34287 and 21, that multiplied together give a palindrome (720027).

The spelling of 3428721 in words is "three million, four hundred twenty-eight thousand, seven hundred twenty-one".