1212001100021 has 4 divisors (see below), whose sum is σ = 1212024901344. Its totient is φ = 1211977298700.

The previous prime is 1212001100003. The next prime is 1212001100047. The reversal of 1212001100021 is 1200011002121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1212001100021 - 2²⁶ = 1211933991157 is a prime.

It is a super-2 number, since 2×1212001100021² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1212001099975 and 1212001100011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212001100071) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11824115 + ... + 11926176.

It is an arithmetic number, because the mean of its divisors is an integer number (303006225336).

Almost surely, 2^{1212001100021} is an apocalyptic number.

It is an amenable number.

1212001100021 is a deficient number, since it is larger than the sum of its proper divisors (23801323).

1212001100021 is an equidigital number, since it uses as much as digits as its factorization.

1212001100021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23801322.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 1212001100021 its reverse (1200011002121), we get a palindrome (2412012102142).

It can be divided in two parts, 121200 and 1100021, that added together give a palindrome (1221221).

The spelling of 1212001100021 in words is "one trillion, two hundred twelve billion, one million, one hundred thousand, twenty-one".