1721913 has 16 divisors (see below), whose sum is σ = 2560320. Its totient is φ = 1022976.

The previous prime is 1721911. The next prime is 1721921. The reversal of 1721913 is 3191271.

It is not a de Polignac number, because 1721913 - 2¹ = 1721911 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1721911) 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, 81 + ... + 1857.

It is an arithmetic number, because the mean of its divisors is an integer number (160020).

2^1721913 is an apocalyptic number.

It is an amenable number.

1721913 is a deficient number, since it is larger than the sum of its proper divisors (838407).

1721913 is a wasteful number, since it uses less digits than its factorization.

1721913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1816.

The product of its digits is 378, while the sum is 24.

The square root of 1721913 is about 1312.2168265954. The cubic root of 1721913 is about 119.8589314511.

The spelling of 1721913 in words is "one million, seven hundred twenty-one thousand, nine hundred thirteen".