20421010 has 32 divisors (see below), whose sum is σ = 40383360. Its totient is φ = 7400448.

The previous prime is 20420999. The next prime is 20421013. The reversal of 20421010 is 1012402.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is not an unprimeable number, because it can be changed into a prime (20421013) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2034 + ... + 6706.

It is an arithmetic number, because the mean of its divisors is an integer number (1261980).

Almost surely, 2^20421010 is an apocalyptic number.

20421010 is a deficient number, since it is larger than the sum of its proper divisors (19962350).

20421010 is a wasteful number, since it uses less digits than its factorization.

20421010 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4722.

The product of its (nonzero) digits is 16, while the sum is 10.

The square root of 20421010 is about 4518.9611638075. The cubic root of 20421010 is about 273.3332127040. Note that the first 3 decimals are identical.

Adding to 20421010 its reverse (1012402), we get a palindrome (21433412).

The spelling of 20421010 in words is "twenty million, four hundred twenty-one thousand, ten".