20605617 has 16 divisors (see below), whose sum is σ = 31029760. Its totient is φ = 13510800.

The previous prime is 20605603. The next prime is 20605621. The reversal of 20605617 is 71650602.

It is not a de Polignac number, because 20605617 - 2⁴ = 20605601 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20601617) 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 15 ways as a sum of consecutive naturals, for example, 4609 + ... + 7902.

It is an arithmetic number, because the mean of its divisors is an integer number (1939360).

Almost surely, 2^20605617 is an apocalyptic number.

20605617 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

20605617 is a deficient number, since it is larger than the sum of its proper divisors (10424143).

20605617 is a wasteful number, since it uses less digits than its factorization.

20605617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12581 (or 12575 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 27.

The square root of 20605617 is about 4539.3410314714. The cubic root of 20605617 is about 274.1543920045.

The spelling of 20605617 in words is "twenty million, six hundred five thousand, six hundred seventeen".