21011200101 has 12 divisors (see below), whose sum is σ = 31169768812. Its totient is φ = 13628886336.

The previous prime is 21011200081. The next prime is 21011200109. The reversal of 21011200101 is 10100211012.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 16448062500 + 4563137601 = 128250^2 + 67551^2 .

It is not a de Polignac number, because 21011200101 - 2¹⁹ = 21010675813 is a prime.

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

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011200109) 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, 31548016 + ... + 31548681.

Almost surely, 2^21011200101 is an apocalyptic number.

It is an amenable number.

21011200101 is a deficient number, since it is larger than the sum of its proper divisors (10158568711).

21011200101 is a wasteful number, since it uses less digits than its factorization.

21011200101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63096740 (or 63096737 counting only the distinct ones).

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

Adding to 21011200101 its reverse (10100211012), we get a palindrome (31111411113).

The spelling of 21011200101 in words is "twenty-one billion, eleven million, two hundred thousand, one hundred one".