21003302121 has 8 divisors (see below), whose sum is σ = 28007820960. Its totient is φ = 14000492352.

The previous prime is 21003302119. The next prime is 21003302149. The reversal of 21003302121 is 12120330012.

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

It is not a de Polignac number, because 21003302121 - 2¹ = 21003302119 is a prime.

It is a super-2 number, since 2×21003302121² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21003302121.

It is not an unprimeable number, because it can be changed into a prime (21003302161) 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, 398311 + ... + 447948.

It is an arithmetic number, because the mean of its divisors is an integer number (3500977620).

Almost surely, 2^21003302121 is an apocalyptic number.

It is an amenable number.

21003302121 is a deficient number, since it is larger than the sum of its proper divisors (7004518839).

21003302121 is an equidigital number, since it uses as much as digits as its factorization.

21003302121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 854535.

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 21003302121 its reverse (12120330012), we get a palindrome (33123632133).

The spelling of 21003302121 in words is "twenty-one billion, three million, three hundred two thousand, one hundred twenty-one".