1001220121 has 8 divisors (see below), whose sum is σ = 1100841984. Its totient is φ = 903031920.

The previous prime is 1001220097. The next prime is 1001220131. The reversal of 1001220121 is 1210221001.

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

It is a cyclic number.

It is not a de Polignac number, because 1001220121 - 2²⁵ = 967665689 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1001220098 and 1001220107.

It is not an unprimeable number, because it can be changed into a prime (1001220131) 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, 356950 + ... + 359743.

It is an arithmetic number, because the mean of its divisors is an integer number (137605248).

Almost surely, 2^1001220121 is an apocalyptic number.

1001220121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1001220121 is a deficient number, since it is larger than the sum of its proper divisors (99621863).

1001220121 is a wasteful number, since it uses less digits than its factorization.

1001220121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 716831.

The product of its (nonzero) digits is 8, while the sum is 10.

The square root of 1001220121 is about 31642.0625275913. The cubic root of 1001220121 is about 1000.4065417014.

Adding to 1001220121 its reverse (1210221001), we get a palindrome (2211441122).

It can be divided in two parts, 1001 and 220121, that added together give a palindrome (221122).

The spelling of 1001220121 in words is "one billion, one million, two hundred twenty thousand, one hundred twenty-one".