1001100121 has 4 divisors (see below), whose sum is σ = 1144114432. Its totient is φ = 858085812.

The previous prime is 1001100091. The next prime is 1001100127. The reversal of 1001100121 is 1210011001.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1210011001 = 479 ⋅2526119.

It is a cyclic number.

It is not a de Polignac number, because 1001100121 - 2¹⁷ = 1000969049 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (7), and also a Moran number because the ratio is a prime number: 143014303 = 1001100121 / (1 + 0 + 0 + 1 + 1 + 0 + 0 + 1 + 2 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1001100127) 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, 71507145 + ... + 71507158.

It is an arithmetic number, because the mean of its divisors is an integer number (286028608).

Almost surely, 2^1001100121 is an apocalyptic number.

It is an amenable number.

1001100121 is a deficient number, since it is larger than the sum of its proper divisors (143014311).

1001100121 is an equidigital number, since it uses as much as digits as its factorization.

1001100121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143014310.

The product of its (nonzero) digits is 2, while the sum is 7.

The square root of 1001100121 is about 31640.1662606251. The cubic root of 1001100121 is about 1000.3665726081.

Adding to 1001100121 its reverse (1210011001), we get a palindrome (2211111122).

The spelling of 1001100121 in words is "one billion, one million, one hundred thousand, one hundred twenty-one".