21221111021001 has 8 divisors (see below), whose sum is σ = 28295024059104. Its totient is φ = 14147302665120.

The previous prime is 21221111020997. The next prime is 21221111021039. The reversal of 21221111021001 is 10012011112212.

It is a happy number.

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

It is not a de Polignac number, because 21221111021001 - 2² = 21221111020997 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21221111021081) 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, 25696315 + ... + 26509296.

It is an arithmetic number, because the mean of its divisors is an integer number (3536878007388).

Almost surely, 2^{21221111021001} is an apocalyptic number.

It is an amenable number.

21221111021001 is a deficient number, since it is larger than the sum of its proper divisors (7073913038103).

21221111021001 is a wasteful number, since it uses less digits than its factorization.

21221111021001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52341111.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 21221111021001 its reverse (10012011112212), we get a palindrome (31233122133213).

The spelling of 21221111021001 in words is "twenty-one trillion, two hundred twenty-one billion, one hundred eleven million, twenty-one thousand, one".