21020010001 has 16 divisors (see below), whose sum is σ = 21372668928. Its totient is φ = 20670728400.

The previous prime is 21020009993. The next prime is 21020010013. The reversal of 21020010001 is 10001002012.

It is a cyclic number.

It is not a de Polignac number, because 21020010001 - 2³ = 21020009993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21020010041) 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, 11479156 + ... + 11480986.

It is an arithmetic number, because the mean of its divisors is an integer number (1335791808).

Almost surely, 2^21020010001 is an apocalyptic number.

It is an amenable number.

21020010001 is a deficient number, since it is larger than the sum of its proper divisors (352658927).

21020010001 is a wasteful number, since it uses less digits than its factorization.

21020010001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2652.

The product of its (nonzero) digits is 4, while the sum is 7.

Adding to 21020010001 its reverse (10001002012), we get a palindrome (31021012013).

The spelling of 21020010001 in words is "twenty-one billion, twenty million, ten thousand, one".