21002010001 has 24 divisors (see below), whose sum is σ = 25878691296. Its totient is φ = 16935811200.

The previous prime is 21002009957. The next prime is 21002010023. The reversal of 21002010001 is 10001020012.

It is not a de Polignac number, because 21002010001 - 2²³ = 20993621393 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (7).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21002010901) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3204610 + ... + 3211156.

It is an arithmetic number, because the mean of its divisors is an integer number (1078278804).

Almost surely, 2^21002010001 is an apocalyptic number.

It is an amenable number.

21002010001 is a deficient number, since it is larger than the sum of its proper divisors (4876681295).

21002010001 is a wasteful number, since it uses less digits than its factorization.

21002010001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10429 (or 10422 counting only the distinct ones).

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

Adding to 21002010001 its reverse (10001020012), we get a palindrome (31003030013).

The spelling of 21002010001 in words is "twenty-one billion, two million, ten thousand, one".