20606661 has 12 divisors (see below), whose sum is σ = 30725760. Its totient is φ = 13294440.

The previous prime is 20606627. The next prime is 20606681. The reversal of 20606661 is 16660602.

It is not a de Polignac number, because 20606661 - 2¹¹ = 20604613 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20606681) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 36651 + ... + 37208.

It is an arithmetic number, because the mean of its divisors is an integer number (2560480).

Almost surely, 2^20606661 is an apocalyptic number.

It is an amenable number.

20606661 is a deficient number, since it is larger than the sum of its proper divisors (10119099).

20606661 is a wasteful number, since it uses less digits than its factorization.

20606661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73896 (or 73893 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The square root of 20606661 is about 4539.4560246796. The cubic root of 20606661 is about 274.1590220099.

The spelling of 20606661 in words is "twenty million, six hundred six thousand, six hundred sixty-one".