20661351 has 8 divisors (see below), whose sum is σ = 27633024. Its totient is φ = 13731960.

The previous prime is 20661323. The next prime is 20661367. The reversal of 20661351 is 15316602.

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

It is not a de Polignac number, because 20661351 - 2⁶ = 20661287 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20661301) 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 7 ways as a sum of consecutive naturals, for example, 9411 + ... + 11396.

It is an arithmetic number, because the mean of its divisors is an integer number (3454128).

Almost surely, 2^20661351 is an apocalyptic number.

20661351 is a deficient number, since it is larger than the sum of its proper divisors (6971673).

20661351 is a wasteful number, since it uses less digits than its factorization.

20661351 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21141.

The product of its (nonzero) digits is 1080, while the sum is 24.

The square root of 20661351 is about 4545.4758826772. The cubic root of 20661351 is about 274.4013467608.

Adding to 20661351 its reverse (15316602), we get a palindrome (35977953).

It can be divided in two parts, 20661 and 351, that added together give a palindrome (21012).

The spelling of 20661351 in words is "twenty million, six hundred sixty-one thousand, three hundred fifty-one".