21001203011 has 4 divisors (see below), whose sum is σ = 22236567912. Its totient is φ = 19765838112.

The previous prime is 21001203007. The next prime is 21001203017. The reversal of 21001203011 is 11030210012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21001203011 - 2² = 21001203007 is a prime.

It is a super-2 number, since 2×21001203011² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21001202983 and 21001203001.

It is not an unprimeable number, because it can be changed into a prime (21001203017) 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, 617682425 + ... + 617682458.

It is an arithmetic number, because the mean of its divisors is an integer number (5559141978).

Almost surely, 2^21001203011 is an apocalyptic number.

21001203011 is a deficient number, since it is larger than the sum of its proper divisors (1235364901).

21001203011 is a wasteful number, since it uses less digits than its factorization.

21001203011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1235364900.

The product of its (nonzero) digits is 12, while the sum is 11.

Adding to 21001203011 its reverse (11030210012), we get a palindrome (32031413023).

The spelling of 21001203011 in words is "twenty-one billion, one million, two hundred three thousand, eleven".