20203642 has 4 divisors (see below), whose sum is σ = 30305466. Its totient is φ = 10101820.

The previous prime is 20203639. The next prime is 20203643. The reversal of 20203642 is 24630202.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 24630202 = 2 ⋅12315101.

It can be written as a sum of positive squares in only one way, i.e., 17214201 + 2989441 = 4149^2 + 1729^2 .

It is not an unprimeable number, because it can be changed into a prime (20203643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5050909 + ... + 5050912.

Almost surely, 2^20203642 is an apocalyptic number.

20203642 is a deficient number, since it is larger than the sum of its proper divisors (10101824).

20203642 is a wasteful number, since it uses less digits than its factorization.

20203642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10101823.

The product of its (nonzero) digits is 576, while the sum is 19.

The square root of 20203642 is about 4494.8461597701. The cubic root of 20203642 is about 272.3599347521.

Adding to 20203642 its reverse (24630202), we get a palindrome (44833844).

The spelling of 20203642 in words is "twenty million, two hundred three thousand, six hundred forty-two".