21012011201 has 4 divisors (see below), whose sum is σ = 21012353472. Its totient is φ = 21011668932.

The previous prime is 21012011191. The next prime is 21012011221. The reversal of 21012011201 is 10211021012.

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 21012011201 - 2²⁶ = 20944902337 is a prime.

It is a super-2 number, since 2×21012011201² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21012011221) 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, 50885 + ... + 211218.

It is an arithmetic number, because the mean of its divisors is an integer number (5253088368).

Almost surely, 2^21012011201 is an apocalyptic number.

It is an amenable number.

21012011201 is a deficient number, since it is larger than the sum of its proper divisors (342271).

21012011201 is an equidigital number, since it uses as much as digits as its factorization.

21012011201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 342270.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 21012011201 its reverse (10211021012), we get a palindrome (31223032213).

The spelling of 21012011201 in words is "twenty-one billion, twelve million, eleven thousand, two hundred one".