21110102001 has 12 divisors (see below), whose sum is σ = 31009190160. Its totient is φ = 13834868760.

The previous prime is 21110101997. The next prime is 21110102009. The reversal of 21110102001 is 10020101112.

It is a happy number.

It is not a de Polignac number, because 21110102001 - 2² = 21110101997 is a prime.

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

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21110102009) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19877155 + ... + 19878216.

It is an arithmetic number, because the mean of its divisors is an integer number (2584099180).

Almost surely, 2^21110102001 is an apocalyptic number.

It is an amenable number.

21110102001 is a deficient number, since it is larger than the sum of its proper divisors (9899088159).

21110102001 is a wasteful number, since it uses less digits than its factorization.

21110102001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39755436 (or 39755433 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 21110102001 its reverse (10020101112), we get a palindrome (31130203113).

The spelling of 21110102001 in words is "twenty-one billion, one hundred ten million, one hundred two thousand, one".