21012011221101 has 4 divisors (see below), whose sum is σ = 28016014961472. Its totient is φ = 14008007480732.

The previous prime is 21012011221081. The next prime is 21012011221127. The reversal of 21012011221101 is 10112211021012.

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 21012011221101 - 2³³ = 21003421286509 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012011221301) 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, 3502001870181 + ... + 3502001870186.

It is an arithmetic number, because the mean of its divisors is an integer number (7004003740368).

Almost surely, 2^{21012011221101} is an apocalyptic number.

It is an amenable number.

21012011221101 is a deficient number, since it is larger than the sum of its proper divisors (7004003740371).

21012011221101 is an equidigital number, since it uses as much as digits as its factorization.

21012011221101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7004003740370.

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

Adding to 21012011221101 its reverse (10112211021012), we get a palindrome (31124222242113).

The spelling of 21012011221101 in words is "twenty-one trillion, twelve billion, eleven million, two hundred twenty-one thousand, one hundred one".