20521442 has 16 divisors (see below), whose sum is σ = 32140800. Its totient is φ = 9815520.

The previous prime is 20521429. The next prime is 20521447. The reversal of 20521442 is 24412502.

It is a happy number.

It is a super-2 number, since 2×20521442² = 842259163518728, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20521447) 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 in 7 ways as a sum of consecutive naturals, for example, 3659 + ... + 7377.

It is an arithmetic number, because the mean of its divisors is an integer number (2008800).

Almost surely, 2^20521442 is an apocalyptic number.

20521442 is a deficient number, since it is larger than the sum of its proper divisors (11619358).

20521442 is a wasteful number, since it uses less digits than its factorization.

20521442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3841.

The product of its (nonzero) digits is 640, while the sum is 20.

The square root of 20521442 is about 4530.0598230045. The cubic root of 20521442 is about 273.7805709414.

Adding to 20521442 its reverse (24412502), we get a palindrome (44933944).

The spelling of 20521442 in words is "twenty million, five hundred twenty-one thousand, four hundred forty-two".