20421003 has 8 divisors (see below), whose sum is σ = 27964048. Its totient is φ = 13245984.

The previous prime is 20420999. The next prime is 20421013. The reversal of 20421003 is 30012402.

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

It is not a de Polignac number, because 20421003 - 2² = 20420999 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20421003.

It is not an unprimeable number, because it can be changed into a prime (20421013) 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, 91876 + ... + 92097.

It is an arithmetic number, because the mean of its divisors is an integer number (3495506).

Almost surely, 2^20421003 is an apocalyptic number.

20421003 is a deficient number, since it is larger than the sum of its proper divisors (7543045).

20421003 is a wasteful number, since it uses less digits than its factorization.

20421003 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 184013.

The product of its (nonzero) digits is 48, while the sum is 12.

The square root of 20421003 is about 4518.9603892931. The cubic root of 20421003 is about 273.3331814726. Note that the first 3 decimals are identical.

Adding to 20421003 its reverse (30012402), we get a palindrome (50433405).

The spelling of 20421003 in words is "twenty million, four hundred twenty-one thousand, three".