21100022001 has 24 divisors (see below), whose sum is σ = 31514805504. Its totient is φ = 13589621280.

The previous prime is 21100021993. The next prime is 21100022023. The reversal of 21100022001 is 10022000112.

It is not a de Polignac number, because 21100022001 - 2³ = 21100021993 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 (21100022071) 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 23 ways as a sum of consecutive naturals, for example, 99355 + ... + 228191.

It is an arithmetic number, because the mean of its divisors is an integer number (1313116896).

Almost surely, 2^21100022001 is an apocalyptic number.

It is an amenable number.

21100022001 is a deficient number, since it is larger than the sum of its proper divisors (10414783503).

21100022001 is a wasteful number, since it uses less digits than its factorization.

21100022001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129461 (or 129458 counting only the distinct ones).

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

Adding to 21100022001 its reverse (10022000112), we get a palindrome (31122022113).

The spelling of 21100022001 in words is "twenty-one billion, one hundred million, twenty-two thousand, one".