1721481 has 16 divisors (see below), whose sum is σ = 2440320. Its totient is φ = 1077120.

The previous prime is 1721477. The next prime is 1721497. The reversal of 1721481 is 1841271.

It is not a de Polignac number, because 1721481 - 2² = 1721477 is a prime.

It is a super-2 number, since 2×1721481² = 5926993666722, which contains 22 as substring.

It is a Curzon number.

It is a nialpdrome in base 8.

It is not an unprimeable number, because it can be changed into a prime (1721441) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4005 + ... + 4413.

It is an arithmetic number, because the mean of its divisors is an integer number (152520).

2^1721481 is an apocalyptic number.

It is an amenable number.

1721481 is a deficient number, since it is larger than the sum of its proper divisors (718839).

1721481 is a wasteful number, since it uses less digits than its factorization.

1721481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 496.

The product of its digits is 448, while the sum is 24.

The square root of 1721481 is about 1312.0522093271. The cubic root of 1721481 is about 119.8489070598.

It can be divided in two parts, 172 and 1481, that added together give a triangular number (1653 = T₅₇).

The spelling of 1721481 in words is "one million, seven hundred twenty-one thousand, four hundred eighty-one".