1221212100101 has 16 divisors (see below), whose sum is σ = 1401820992000. Its totient is φ = 1042142656128.

The previous prime is 1221212100077. The next prime is 1221212100107. The reversal of 1221212100101 is 1010012121221.

It is not a de Polignac number, because 1221212100101 - 2³⁴ = 1204032230917 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 (1221212100107) 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, 7699271 + ... + 7856283.

It is an arithmetic number, because the mean of its divisors is an integer number (87613812000).

Almost surely, 2^{1221212100101} is an apocalyptic number.

It is an amenable number.

1221212100101 is a deficient number, since it is larger than the sum of its proper divisors (180608891899).

1221212100101 is a wasteful number, since it uses less digits than its factorization.

1221212100101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161908.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 1221212100101 its reverse (1010012121221), we get a palindrome (2231224221322).

It can be divided in two parts, 122121 and 2100101, that added together give a palindrome (2222222).

The spelling of 1221212100101 in words is "one trillion, two hundred twenty-one billion, two hundred twelve million, one hundred thousand, one hundred one".