1729981 has 4 divisors (see below), whose sum is σ = 1887264. Its totient is φ = 1572700.

The previous prime is 1729961. The next prime is 1730041. The reversal of 1729981 is 1899271.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1729981 - 2¹⁹ = 1205693 is a prime.

It is a super-2 number, since 2×1729981² = 5985668520722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1729981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1729901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 78625 + ... + 78646.

It is an arithmetic number, because the mean of its divisors is an integer number (471816).

2^1729981 is an apocalyptic number.

1729981 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1729981 is a deficient number, since it is larger than the sum of its proper divisors (157283).

1729981 is a wasteful number, since it uses less digits than its factorization.

1729981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 157282.

The product of its digits is 9072, while the sum is 37.

The square root of 1729981 is about 1315.2874210605. The cubic root of 1729981 is about 120.0458389692.

It can be divided in two parts, 172 and 9981, that added together give a triangular number (10153 = T₁₄₂).

The spelling of 1729981 in words is "one million, seven hundred twenty-nine thousand, nine hundred eighty-one".