20616613 has 4 divisors (see below), whose sum is σ = 20668428. Its totient is φ = 20564800.

The previous prime is 20616601. The next prime is 20616623. The reversal of 20616613 is 31661602.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15499969 + 5116644 = 3937^2 + 2262^2 .

It is a cyclic number.

It is not a de Polignac number, because 20616613 - 2¹⁷ = 20485541 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20616623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25306 + ... + 26107.

It is an arithmetic number, because the mean of its divisors is an integer number (5167107).

Almost surely, 2^20616613 is an apocalyptic number.

It is an amenable number.

20616613 is a deficient number, since it is larger than the sum of its proper divisors (51815).

20616613 is an equidigital number, since it uses as much as digits as its factorization.

20616613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51814.

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 20616613 is about 4540.5520589461. The cubic root of 20616613 is about 274.2031499980.

The spelling of 20616613 in words is "twenty million, six hundred sixteen thousand, six hundred thirteen".