1212105 has 16 divisors (see below), whose sum is σ = 2041920. Its totient is φ = 612288.

The previous prime is 1212103. The next prime is 1212119. The reversal of 1212105 is 5012121.

It is not a de Polignac number, because 1212105 - 2¹ = 1212103 is a prime.

It is an Ulam number.

It is an alternating number because its digits alternate between odd and even.

It is not an unprimeable number, because it can be changed into a prime (1212103) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1842 + ... + 2411.

It is an arithmetic number, because the mean of its divisors is an integer number (127620).

2^1212105 is an apocalyptic number.

1212105 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1212105 is a deficient number, since it is larger than the sum of its proper divisors (829815).

1212105 is a wasteful number, since it uses less digits than its factorization.

1212105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4280.

The product of its (nonzero) digits is 20, while the sum is 12.

The square root of 1212105 is about 1100.9564024066. The cubic root of 1212105 is about 106.6219810656.

Adding to 1212105 its reverse (5012121), we get a palindrome (6224226).

It can be divided in two parts, 1212 and 105, that multiplied together give a triangular number (127260 = T₅₀₄).

The spelling of 1212105 in words is "one million, two hundred twelve thousand, one hundred five".