12121111010021 has 8 divisors (see below), whose sum is σ = 13053687607800. Its totient is φ = 11188560618432.

The previous prime is 12121111010011. The next prime is 12121111010053. The reversal of 12121111010021 is 12001011112121.

It can be written as a sum of positive squares in 4 ways, for example, as 326103813025 + 11795007196996 = 571055^2 + 3434386^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12121111010021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12121111009978 and 12121111010005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12121111010011) 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, 5585630 + ... + 7445903.

It is an arithmetic number, because the mean of its divisors is an integer number (1631710950975).

Almost surely, 2^{12121111010021} is an apocalyptic number.

It is an amenable number.

12121111010021 is a deficient number, since it is larger than the sum of its proper divisors (932576597779).

12121111010021 is a wasteful number, since it uses less digits than its factorization.

12121111010021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13103095.

The product of its (nonzero) digits is 8, while the sum is 14.

Adding to 12121111010021 its reverse (12001011112121), we get a palindrome (24122122122142).

The spelling of 12121111010021 in words is "twelve trillion, one hundred twenty-one billion, one hundred eleven million, ten thousand, twenty-one".