20557946 has 8 divisors (see below), whose sum is σ = 31062420. Its totient is φ = 10203808.

The previous prime is 20557919. The next prime is 20557949. The reversal of 20557946 is 64975502.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 18705625 + 1852321 = 4325^2 + 1361^2 .

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

It is not an unprimeable number, because it can be changed into a prime (20557949) 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, 37241 + ... + 37788.

Almost surely, 2^20557946 is an apocalyptic number.

20557946 is a deficient number, since it is larger than the sum of its proper divisors (10504474).

20557946 is a wasteful number, since it uses less digits than its factorization.

20557946 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75168.

The product of its (nonzero) digits is 75600, while the sum is 38.

The square root of 20557946 is about 4534.0871187043. The cubic root of 20557946 is about 273.9428104486.

It can be divided in two parts, 2055 and 7946, that added together give a palindrome (10001).

The spelling of 20557946 in words is "twenty million, five hundred fifty-seven thousand, nine hundred forty-six".