20442357 has 12 divisors (see below), whose sum is σ = 31799404. Its totient is φ = 12579840.

The previous prime is 20442349. The next prime is 20442397. The reversal of 20442357 is 75324402.

It can be written as a sum of positive squares in 2 ways, for example, as 2852721 + 17589636 = 1689^2 + 4194^2 .

It is not a de Polignac number, because 20442357 - 2³ = 20442349 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20442357.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20442397) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 87244 + ... + 87477.

Almost surely, 2^20442357 is an apocalyptic number.

It is an amenable number.

20442357 is a deficient number, since it is larger than the sum of its proper divisors (11357047).

20442357 is a wasteful number, since it uses less digits than its factorization.

20442357 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 174740 (or 174737 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 27.

The square root of 20442357 is about 4521.3224835218. The cubic root of 20442357 is about 273.4284220355.

Adding to 20442357 its reverse (75324402), we get a palindrome (95766759).

It can be divided in two parts, 204423 and 57, that added together give a triangular number (204480 = T₆₃₉).

The spelling of 20442357 in words is "twenty million, four hundred forty-two thousand, three hundred fifty-seven".