21012002121001 has 4 divisors (see below), whose sum is σ = 21012133800592. Its totient is φ = 21011870441412.

The previous prime is 21012002120981. The next prime is 21012002121017. The reversal of 21012002121001 is 10012120021012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21012002121001 - 2⁹ = 21012002120489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21012002121041) 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, 65600151 + ... + 65919676.

It is an arithmetic number, because the mean of its divisors is an integer number (5253033450148).

Almost surely, 2^{21012002121001} is an apocalyptic number.

It is an amenable number.

21012002121001 is a deficient number, since it is larger than the sum of its proper divisors (131679591).

21012002121001 is a wasteful number, since it uses less digits than its factorization.

21012002121001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131679590.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21012002121001 its reverse (10012120021012), we get a palindrome (31024122142013).

The spelling of 21012002121001 in words is "twenty-one trillion, twelve billion, two million, one hundred twenty-one thousand, one".