21612101 has 16 divisors (see below), whose sum is σ = 26611200. Its totient is φ = 17137008.

The previous prime is 21612091. The next prime is 21612103. The reversal of 21612101 is 10121612.

It is not a de Polignac number, because 21612101 - 2⁶ = 21612037 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21612103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3830 + ... + 7608.

It is an arithmetic number, because the mean of its divisors is an integer number (1663200).

Almost surely, 2^21612101 is an apocalyptic number.

It is an amenable number.

21612101 is a deficient number, since it is larger than the sum of its proper divisors (4999099).

21612101 is a wasteful number, since it uses less digits than its factorization.

21612101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3848.

The product of its (nonzero) digits is 24, while the sum is 14.

The square root of 21612101 is about 4648.8816934829. The cubic root of 21612101 is about 278.5473275915.

Adding to 21612101 its reverse (10121612), we get a palindrome (31733713).

It can be divided in two parts, 21612 and 101, that multiplied together give a palindrome (2182812).

The spelling of 21612101 in words is "twenty-one million, six hundred twelve thousand, one hundred one".