1616521 has 4 divisors (see below), whose sum is σ = 1619200. Its totient is φ = 1613844.

The previous prime is 1616519. The next prime is 1616533. The reversal of 1616521 is 1256161.

1616521 is nontrivially palindromic in base 4.

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 1616521 - 2¹ = 1616519 is a prime.

It is a super-2 number, since 2×1616521² = 5226280286882, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1616492 and 1616501.

It is not an unprimeable number, because it can be changed into a prime (1616551) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40 + ... + 1798.

It is an arithmetic number, because the mean of its divisors is an integer number (404800).

2^1616521 is an apocalyptic number.

It is an amenable number.

1616521 is a deficient number, since it is larger than the sum of its proper divisors (2679).

1616521 is an equidigital number, since it uses as much as digits as its factorization.

1616521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2678.

The product of its digits is 360, while the sum is 22.

The square root of 1616521 is about 1271.4247913266. The cubic root of 1616521 is about 117.3618959892.

Subtracting from 1616521 its product of digits (360), we obtain a palindrome (1616161).

The spelling of 1616521 in words is "one million, six hundred sixteen thousand, five hundred twenty-one".