1211210001 has 12 divisors (see below), whose sum is σ = 1750869120. Its totient is φ = 806853240.

The previous prime is 1211209973. The next prime is 1211210009. The reversal of 1211210001 is 1000121121.

It is a happy number.

It is not a de Polignac number, because 1211210001 - 2⁷ = 1211209873 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is not an unprimeable number, because it can be changed into a prime (1211210009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 39145 + ... + 62886.

It is an arithmetic number, because the mean of its divisors is an integer number (145905760).

Almost surely, 2^1211210001 is an apocalyptic number.

It is an amenable number.

1211210001 is a deficient number, since it is larger than the sum of its proper divisors (539659119).

1211210001 is a wasteful number, since it uses less digits than its factorization.

1211210001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103356 (or 103353 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

The square root of 1211210001 is about 34802.4424573908. The cubic root of 1211210001 is about 1065.9573194710.

Adding to 1211210001 its reverse (1000121121), we get a palindrome (2211331122).

The spelling of 1211210001 in words is "one billion, two hundred eleven million, two hundred ten thousand, one".