1613721 has 8 divisors (see below), whose sum is σ = 2165184. Its totient is φ = 1069040.

The previous prime is 1613713. The next prime is 1613741. The reversal of 1613721 is 1273161.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1613721 - 2³ = 1613713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1613741) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1110 + ... + 2111.

It is an arithmetic number, because the mean of its divisors is an integer number (270648).

2^1613721 is an apocalyptic number.

It is an amenable number.

1613721 is a deficient number, since it is larger than the sum of its proper divisors (551463).

1613721 is a wasteful number, since it uses less digits than its factorization.

1613721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3391.

The product of its digits is 252, while the sum is 21.

The square root of 1613721 is about 1270.3231872244. The cubic root of 1613721 is about 117.2940954010.

Adding to 1613721 its reverse (1273161), we get a palindrome (2886882).

The spelling of 1613721 in words is "one million, six hundred thirteen thousand, seven hundred twenty-one".