1721402 has 4 divisors (see below), whose sum is σ = 2582106. Its totient is φ = 860700.

The previous prime is 1721383. The next prime is 1721407. The reversal of 1721402 is 2041271.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 2041271 = 127 ⋅16073.

It can be written as a sum of positive squares in only one way, i.e., 1713481 + 7921 = 1309^2 + 89^2 .

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 as a sum of consecutive naturals, namely, 430349 + ... + 430352.

2^1721402 is an apocalyptic number.

1721402 is a deficient number, since it is larger than the sum of its proper divisors (860704).

1721402 is an equidigital number, since it uses as much as digits as its factorization.

1721402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 860703.

The product of its (nonzero) digits is 112, while the sum is 17.

The square root of 1721402 is about 1312.0221034723. The cubic root of 1721402 is about 119.8470737142.

Adding to 1721402 its reverse (2041271), we get a palindrome (3762673).

The spelling of 1721402 in words is "one million, seven hundred twenty-one thousand, four hundred two".