1721408 has 28 divisors (see below), whose sum is σ = 3680460. Its totient is φ = 794112.

The previous prime is 1721407. The next prime is 1721417. The reversal of 1721408 is 8041271.

It can be written as a sum of positive squares in 2 ways, for example, as 262144 + 1459264 = 512^2 + 1208^2 .

It is a hoax number, since the sum of its digits (23) coincides with the sum of the digits of its distinct prime factors.

It is a nialpdrome in base 8.

It is not an unprimeable number, because it can be changed into a prime (1721407) 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, 203 + ... + 1866.

It is an arithmetic number, because the mean of its divisors is an integer number (131445).

2^1721408 is an apocalyptic number.

It is an amenable number.

1721408 is an abundant number, since it is smaller than the sum of its proper divisors (1959052).

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

1721408 is a wasteful number, since it uses less digits than its factorization.

1721408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2094 (or 2084 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 23.

The square root of 1721408 is about 1312.0243900172. The cubic root of 1721408 is about 119.8472129576.

Adding to 1721408 its reverse (8041271), we get a palindrome (9762679).

The spelling of 1721408 in words is "one million, seven hundred twenty-one thousand, four hundred eight".