21002121006 has 8 divisors (see below), whose sum is σ = 42004242024. Its totient is φ = 7000707000.

The previous prime is 21002120999. The next prime is 21002121013. The reversal of 21002121006 is 60012120012.

It is an interprime number because it is at equal distance from previous prime (21002120999) and next prime (21002121013).

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

21002121006 is an admirable number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1750176745 + ... + 1750176756.

It is an arithmetic number, because the mean of its divisors is an integer number (5250530253).

Almost surely, 2^21002121006 is an apocalyptic number.

21002121006 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21002121006 is a wasteful number, since it uses less digits than its factorization.

21002121006 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3500353506.

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 21002121006 its reverse (60012120012), we get a palindrome (81014241018).

The spelling of 21002121006 in words is "twenty-one billion, two million, one hundred twenty-one thousand, six".