1211002221 has 64 divisors (see below), whose sum is σ = 2017935360. Its totient is φ = 635040000.

The previous prime is 1211002181. The next prime is 1211002291. The reversal of 1211002221 is 1222001121.

It is not a de Polignac number, because 1211002221 - 2⁹ = 1211001709 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1211002197 and 1211002206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211002291) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 822516 + ... + 823986.

It is an arithmetic number, because the mean of its divisors is an integer number (31530240).

Almost surely, 2^1211002221 is an apocalyptic number.

1211002221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1211002221 is a deficient number, since it is larger than the sum of its proper divisors (806933139).

1211002221 is a wasteful number, since it uses less digits than its factorization.

1211002221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1618.

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 1211002221 is about 34799.4571940426. The cubic root of 1211002221 is about 1065.8963618948.

Adding to 1211002221 its reverse (1222001121), we get a palindrome (2433003342).

It can be divided in two parts, 121100 and 2221, that added together give a palindrome (123321).

The spelling of 1211002221 in words is "one billion, two hundred eleven million, two thousand, two hundred twenty-one".