20521443 has 8 divisors (see below), whose sum is σ = 28029456. Its totient is φ = 13347200.

The previous prime is 20521429. The next prime is 20521447. The reversal of 20521443 is 34412502.

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

It is a cyclic number.

It is not a de Polignac number, because 20521443 - 2⁶ = 20521379 is a prime.

It is a super-2 number, since 2×20521443² = 842259245604498, 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 polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 83298 + ... + 83543.

It is an arithmetic number, because the mean of its divisors is an integer number (3503682).

Almost surely, 2^20521443 is an apocalyptic number.

20521443 is a deficient number, since it is larger than the sum of its proper divisors (7508013).

20521443 is a wasteful number, since it uses less digits than its factorization.

20521443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166885.

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 20521443 is about 4530.0599333784. The cubic root of 20521443 is about 273.7805753885.

Adding to 20521443 its reverse (34412502), we get a palindrome (54933945).

The spelling of 20521443 in words is "twenty million, five hundred twenty-one thousand, four hundred forty-three".