1616544521 has 4 divisors (see below), whose sum is σ = 1632239232. Its totient is φ = 1600849812.

The previous prime is 1616544509. The next prime is 1616544547. The reversal of 1616544521 is 1254456161.

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 a de Polignac number, because none of the positive numbers 2^k-1616544521 is a prime.

It is a super-2 number, since 2×1616544521² = 5226432376750238882, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1616544221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7847201 + ... + 7847406.

It is an arithmetic number, because the mean of its divisors is an integer number (408059808).

Almost surely, 2^1616544521 is an apocalyptic number.

It is an amenable number.

1616544521 is a deficient number, since it is larger than the sum of its proper divisors (15694711).

1616544521 is a wasteful number, since it uses less digits than its factorization.

1616544521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15694710.

The product of its digits is 28800, while the sum is 35.

The square root of 1616544521 is about 40206.2746471244. The cubic root of 1616544521 is about 1173.6246520659.

The spelling of 1616544521 in words is "one billion, six hundred sixteen million, five hundred forty-four thousand, five hundred twenty-one".