21020450 has 24 divisors (see below), whose sum is σ = 42653520. Its totient is φ = 7643600.

The previous prime is 21020437. The next prime is 21020501. The reversal of 21020450 is 5402012.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 18560 + ... + 19659.

It is an arithmetic number, because the mean of its divisors is an integer number (1777230).

Almost surely, 2^21020450 is an apocalyptic number.

21020450 is an abundant number, since it is smaller than the sum of its proper divisors (21633070).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21020450 is a wasteful number, since it uses less digits than its factorization.

21020450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38242 (or 38237 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 14.

The square root of 21020450 is about 4584.8064299379. The cubic root of 21020450 is about 275.9819441384.

Adding to 21020450 its reverse (5402012), we get a palindrome (26422462).

The spelling of 21020450 in words is "twenty-one million, twenty thousand, four hundred fifty".