1021211205 has 24 divisors (see below), whose sum is σ = 1900704672. Its totient is φ = 466839072.

The previous prime is 1021211189. The next prime is 1021211209. The reversal of 1021211205 is 5021121201.

It is not a de Polignac number, because 1021211205 - 2⁴ = 1021211189 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021211209) 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 23 ways as a sum of consecutive naturals, for example, 693967 + ... + 695436.

It is an arithmetic number, because the mean of its divisors is an integer number (79196028).

Almost surely, 2^1021211205 is an apocalyptic number.

1021211205 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1021211205 is a deficient number, since it is larger than the sum of its proper divisors (879493467).

1021211205 is a wasteful number, since it uses less digits than its factorization.

1021211205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1389425 (or 1389418 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 15.

The square root of 1021211205 is about 31956.3953693154. The cubic root of 1021211205 is about 1007.0209919733.

Adding to 1021211205 its reverse (5021121201), we get a palindrome (6042332406).

It can be divided in two parts, 1021 and 211205, that added together give a triangular number (212226 = T₆₅₁).

The spelling of 1021211205 in words is "one billion, twenty-one million, two hundred eleven thousand, two hundred five".