21010221007 has 4 divisors (see below), whose sum is σ = 21578064856. Its totient is φ = 20442377160.

The previous prime is 21010220999. The next prime is 21010221053. The reversal of 21010221007 is 70012201012.

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

It is not a de Polignac number, because 21010221007 - 2³ = 21010220999 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 (21010221607) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 283921869 + ... + 283921942.

It is an arithmetic number, because the mean of its divisors is an integer number (5394516214).

Almost surely, 2^21010221007 is an apocalyptic number.

21010221007 is a deficient number, since it is larger than the sum of its proper divisors (567843849).

21010221007 is an equidigital number, since it uses as much as digits as its factorization.

21010221007 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 567843848.

The product of its (nonzero) digits is 56, while the sum is 16.

Adding to 21010221007 its reverse (70012201012), we get a palindrome (91022422019).

The spelling of 21010221007 in words is "twenty-one billion, ten million, two hundred twenty-one thousand, seven".