20550661 has 8 divisors (see below), whose sum is σ = 21492864. Its totient is φ = 19612560.

The previous prime is 20550659. The next prime is 20550667. The reversal of 20550661 is 16605502.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20550661 - 2¹ = 20550659 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 (20550667) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14191 + ... + 15571.

It is an arithmetic number, because the mean of its divisors is an integer number (2686608).

Almost surely, 2^20550661 is an apocalyptic number.

It is an amenable number.

20550661 is a deficient number, since it is larger than the sum of its proper divisors (942203).

20550661 is a wasteful number, since it uses less digits than its factorization.

20550661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2051.

The product of its (nonzero) digits is 1800, while the sum is 25.

The square root of 20550661 is about 4533.2836884537. The cubic root of 20550661 is about 273.9104481177.

The spelling of 20550661 in words is "twenty million, five hundred fifty thousand, six hundred sixty-one".