12121001 has 4 divisors (see below), whose sum is σ = 12202500. Its totient is φ = 12039504.

The previous prime is 12120989. The next prime is 12121009. The reversal of 12121001 is 10012121.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 561001 + 11560000 = 749^2 + 3400^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12121001 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 12121001.

It is not an unprimeable number, because it can be changed into a prime (12121009) 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, 40526 + ... + 40823.

It is an arithmetic number, because the mean of its divisors is an integer number (3050625).

Almost surely, 2^12121001 is an apocalyptic number.

It is an amenable number.

12121001 is a deficient number, since it is larger than the sum of its proper divisors (81499).

12121001 is an equidigital number, since it uses as much as digits as its factorization.

12121001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81498.

The product of its (nonzero) digits is 4, while the sum is 8.

The square root of 12121001 is about 3481.5227990062. The cubic root of 12121001 is about 229.7097851887.

Adding to 12121001 its reverse (10012121), we get a palindrome (22133122).

The spelling of 12121001 in words is "twelve million, one hundred twenty-one thousand, one".