21011020001 has 16 divisors (see below), whose sum is σ = 22485859200. Its totient is φ = 19563052800.

The previous prime is 21011019973. The next prime is 21011020061. The reversal of 21011020001 is 10002011012.

It is a cyclic number.

It is not a de Polignac number, because 21011020001 - 2¹⁴ = 21011003617 is a prime.

It is a super-2 number, since 2×21011020001² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21011020061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2397710 + ... + 2406456.

It is an arithmetic number, because the mean of its divisors is an integer number (1405366200).

Almost surely, 2^21011020001 is an apocalyptic number.

It is an amenable number.

21011020001 is a deficient number, since it is larger than the sum of its proper divisors (1474839199).

21011020001 is a wasteful number, since it uses less digits than its factorization.

21011020001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10264.

The product of its (nonzero) digits is 4, while the sum is 8.

Adding to 21011020001 its reverse (10002011012), we get a palindrome (31013031013).

The spelling of 21011020001 in words is "twenty-one billion, eleven million, twenty thousand, one".