21122101 has 16 divisors (see below), whose sum is σ = 28361088. Its totient is φ = 15192000.

The previous prime is 21122099. The next prime is 21122111. The reversal of 21122101 is 10122112.

It is a cyclic number.

It is not a de Polignac number, because 21122101 - 2¹ = 21122099 is a prime.

It is a super-2 number, since 2×21122101² = 892286301308402, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21122111) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9550 + ... + 11551.

It is an arithmetic number, because the mean of its divisors is an integer number (1772568).

Almost surely, 2^21122101 is an apocalyptic number.

It is an amenable number.

21122101 is a deficient number, since it is larger than the sum of its proper divisors (7238987).

21122101 is a wasteful number, since it uses less digits than its factorization.

21122101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21132.

The product of its (nonzero) digits is 8, while the sum is 10.

The square root of 21122101 is about 4595.8786972678. The cubic root of 21122101 is about 276.4260948051.

Adding to 21122101 its reverse (10122112), we get a palindrome (31244213).

The spelling of 21122101 in words is "twenty-one million, one hundred twenty-two thousand, one hundred one".