21011111010101 has 8 divisors (see below), whose sum is σ = 21549394500480. Its totient is φ = 20475084474432.

The previous prime is 21011111010067. The next prime is 21011111010103. The reversal of 21011111010101 is 10101011111012.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21011111010101 - 2⁶ = 21011111010037 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 (21011111010103) 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, 564219821 + ... + 564257058.

It is an arithmetic number, because the mean of its divisors is an integer number (2693674312560).

Almost surely, 2^{21011111010101} is an apocalyptic number.

It is an amenable number.

21011111010101 is a deficient number, since it is larger than the sum of its proper divisors (538283490379).

21011111010101 is a wasteful number, since it uses less digits than its factorization.

21011111010101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1128477355.

The product of its (nonzero) digits is 2, while the sum is 11.

Adding to 21011111010101 its reverse (10101011111012), we get a palindrome (31112122121113).

The spelling of 21011111010101 in words is "twenty-one trillion, eleven billion, one hundred eleven million, ten thousand, one hundred one".