1210001221 has 16 divisors (see below), whose sum is σ = 1426440960. Its totient is φ = 1011885120.

The previous prime is 1210001171. The next prime is 1210001267. The reversal of 1210001221 is 1221000121.

It is a cyclic number.

It is not a de Polignac number, because 1210001221 - 2¹⁵ = 1209968453 is a prime.

It is a Duffinian number.

1210001221 is a modest number, since divided by 1221 gives 1210 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 1210001198 and 1210001207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1210001291) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27460 + ... + 56338.

It is an arithmetic number, because the mean of its divisors is an integer number (89152560).

Almost surely, 2^1210001221 is an apocalyptic number.

1210001221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1210001221 is a deficient number, since it is larger than the sum of its proper divisors (216439739).

1210001221 is a wasteful number, since it uses less digits than its factorization.

1210001221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29196.

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

The square root of 1210001221 is about 34785.0718124888. The cubic root of 1210001221 is about 1065.6025951963.

Adding to 1210001221 its reverse (1221000121), we get a palindrome (2431001342).

It can be divided in two parts, 121000 and 1221, that added together give a palindrome (122221).

The spelling of 1210001221 in words is "one billion, two hundred ten million, one thousand, two hundred twenty-one".