21121011021001 has 4 divisors (see below), whose sum is σ = 21121064150400. Its totient is φ = 21120957891604.

The previous prime is 21121011020999. The next prime is 21121011021007. The reversal of 21121011021001 is 10012011012112.

It is a happy number.

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 21121011021001 - 2¹ = 21121011020999 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21121011021007) 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, 25963861 + ... + 26764978.

It is an arithmetic number, because the mean of its divisors is an integer number (5280266037600).

Almost surely, 2^{21121011021001} is an apocalyptic number.

It is an amenable number.

21121011021001 is a deficient number, since it is larger than the sum of its proper divisors (53129399).

21121011021001 is an equidigital number, since it uses as much as digits as its factorization.

21121011021001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53129398.

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

Adding to 21121011021001 its reverse (10012011012112), we get a palindrome (31133022033113).

The spelling of 21121011021001 in words is "twenty-one trillion, one hundred twenty-one billion, eleven million, twenty-one thousand, one".