21200101 has 4 divisors (see below), whose sum is σ = 22830892. Its totient is φ = 19569312.

The previous prime is 21200093. The next prime is 21200117. The reversal of 21200101 is 10100212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13883076 + 7317025 = 3726^2 + 2705^2 .

It is a cyclic number.

It is not a de Polignac number, because 21200101 - 2³ = 21200093 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21200171) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 815376 + ... + 815401.

It is an arithmetic number, because the mean of its divisors is an integer number (5707723).

Almost surely, 2^21200101 is an apocalyptic number.

It is an amenable number.

21200101 is a deficient number, since it is larger than the sum of its proper divisors (1630791).

21200101 is a wasteful number, since it uses less digits than its factorization.

21200101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1630790.

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

The square root of 21200101 is about 4604.3567411746. The cubic root of 21200101 is about 276.7659402457.

Adding to 21200101 its reverse (10100212), we get a palindrome (31300313).

The spelling of 21200101 in words is "twenty-one million, two hundred thousand, one hundred one".