21111220101 has 8 divisors (see below), whose sum is σ = 28802905120. Its totient is φ = 13746840912.

The previous prime is 21111220073. The next prime is 21111220111. The reversal of 21111220101 is 10102211112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21111220101 - 2⁶ = 21111220037 is a prime.

It is a super-2 number, since 2×21111220101² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21111220111) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 81826306 + ... + 81826563.

It is an arithmetic number, because the mean of its divisors is an integer number (3600363140).

Almost surely, 2^21111220101 is an apocalyptic number.

It is an amenable number.

21111220101 is a deficient number, since it is larger than the sum of its proper divisors (7691685019).

21111220101 is a wasteful number, since it uses less digits than its factorization.

21111220101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 163652915.

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 21111220101 its reverse (10102211112), we get a palindrome (31213431213).

The spelling of 21111220101 in words is "twenty-one billion, one hundred eleven million, two hundred twenty thousand, one hundred one".