21210121101001 has 12 divisors (see below), whose sum is σ = 25047302226816. Its totient is φ = 17593648833960.

The previous prime is 21210121100981. The next prime is 21210121101011. The reversal of 21210121101001 is 10010112101212.

It is a happy number.

It is not a de Polignac number, because 21210121101001 - 2⁹ = 21210121100489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21210121101011) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1576485105 + ... + 1576498558.

It is an arithmetic number, because the mean of its divisors is an integer number (2087275185568).

Almost surely, 2^{21210121101001} is an apocalyptic number.

It is an amenable number.

21210121101001 is a deficient number, since it is larger than the sum of its proper divisors (3837181125815).

21210121101001 is an equidigital number, since it uses as much as digits as its factorization.

21210121101001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3152983732 (or 3152983701 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 21210121101001 its reverse (10010112101212), we get a palindrome (31220233202213).

The spelling of 21210121101001 in words is "twenty-one trillion, two hundred ten billion, one hundred twenty-one million, one hundred one thousand, one".