21022100001 has 18 divisors (see below), whose sum is σ = 35322849042. Its totient is φ = 12012628320.

The previous prime is 21022099993. The next prime is 21022100003. The reversal of 21022100001 is 10000122012.

It can be written as a sum of positive squares in only one way, i.e., 13554547776 + 7467552225 = 116424^2 + 86415^2 .

It is not a de Polignac number, because 21022100001 - 2³ = 21022099993 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is not an unprimeable number, because it can be changed into a prime (21022100003) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 23834140 + ... + 23835021.

Almost surely, 2^21022100001 is an apocalyptic number.

21022100001 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21022100001 is a deficient number, since it is larger than the sum of its proper divisors (14300749041).

21022100001 is a wasteful number, since it uses less digits than its factorization.

21022100001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47669181 (or 47669171 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 21022100001 its reverse (10000122012), we get a palindrome (31022222013).

The spelling of 21022100001 in words is "twenty-one billion, twenty-two million, one hundred thousand, one".