20100221501 has 4 divisors (see below), whose sum is σ = 20101097052. Its totient is φ = 20099345952.

The previous prime is 20100221483. The next prime is 20100221503. The reversal of 20100221501 is 10512200102.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 11051265625 + 9048955876 = 105125^2 + 95126^2 .

It is a cyclic number.

It is not a de Polignac number, because 20100221501 - 2²² = 20096027197 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20100221503) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 402386 + ... + 449571.

It is an arithmetic number, because the mean of its divisors is an integer number (5025274263).

Almost surely, 2^20100221501 is an apocalyptic number.

It is an amenable number.

20100221501 is a deficient number, since it is larger than the sum of its proper divisors (875551).

20100221501 is an equidigital number, since it uses as much as digits as its factorization.

20100221501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 875550.

The product of its (nonzero) digits is 40, while the sum is 14.

Adding to 20100221501 its reverse (10512200102), we get a palindrome (30612421603).

The spelling of 20100221501 in words is "twenty billion, one hundred million, two hundred twenty-one thousand, five hundred one".