1021211001 has 24 divisors (see below), whose sum is σ = 1495472160. Its totient is φ = 671426496.

The previous prime is 1021210979. The next prime is 1021211003. The reversal of 1021211001 is 1001121201.

It is a happy number.

It is not a de Polignac number, because 1021211001 - 2¹⁴ = 1021194617 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 (1021211003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 699210 + ... + 700668.

It is an arithmetic number, because the mean of its divisors is an integer number (62311340).

Almost surely, 2^1021211001 is an apocalyptic number.

It is an amenable number.

1021211001 is a deficient number, since it is larger than the sum of its proper divisors (474261159).

1021211001 is a wasteful number, since it uses less digits than its factorization.

1021211001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2485 (or 2482 counting only the distinct ones).

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

The square root of 1021211001 is about 31956.3921774658. The cubic root of 1021211001 is about 1007.0209249182.

Adding to 1021211001 its reverse (1001121201), we get a palindrome (2022332202).

The spelling of 1021211001 in words is "one billion, twenty-one million, two hundred eleven thousand, one".