1721396 has 12 divisors (see below), whose sum is σ = 3023748. Its totient is φ = 857472.

The previous prime is 1721383. The next prime is 1721407. The reversal of 1721396 is 6931271.

It can be written as a sum of positive squares in 2 ways, for example, as 792100 + 929296 = 890^2 + 964^2 .

It is a super-3 number, since 3×1721396³ = 15302543513433321408, which contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 710 + ... + 1986.

It is an arithmetic number, because the mean of its divisors is an integer number (251979).

2^1721396 is an apocalyptic number.

It is an amenable number.

1721396 is a deficient number, since it is larger than the sum of its proper divisors (1302352).

1721396 is a wasteful number, since it uses less digits than its factorization.

1721396 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1618 (or 1616 counting only the distinct ones).

The product of its digits is 2268, while the sum is 29.

The square root of 1721396 is about 1312.0198169235. The cubic root of 1721396 is about 119.8469344705.

The spelling of 1721396 in words is "one million, seven hundred twenty-one thousand, three hundred ninety-six".