1221211071 has 12 divisors (see below), whose sum is σ = 1767754872. Its totient is φ = 812394576.

The previous prime is 1221211067. The next prime is 1221211127. The reversal of 1221211071 is 1701121221.

It is not a de Polignac number, because 1221211071 - 2² = 1221211067 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221211021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 141076 + ... + 149481.

It is an arithmetic number, because the mean of its divisors is an integer number (147312906).

Almost surely, 2^1221211071 is an apocalyptic number.

1221211071 is a deficient number, since it is larger than the sum of its proper divisors (546543801).

1221211071 is a wasteful number, since it uses less digits than its factorization.

1221211071 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 291030 (or 291027 counting only the distinct ones).

The product of its (nonzero) digits is 56, while the sum is 18.

The square root of 1221211071 is about 34945.8305238264. The cubic root of 1221211071 is about 1068.8831829922.

Adding to 1221211071 its reverse (1701121221), we get a palindrome (2922332292).

The spelling of 1221211071 in words is "one billion, two hundred twenty-one million, two hundred eleven thousand, seventy-one".