1212628709 has 4 divisors (see below), whose sum is σ = 1214695104. Its totient is φ = 1210562316.

The previous prime is 1212628693. The next prime is 1212628721. The reversal of 1212628709 is 9078262121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 9078262121 = 1663 ⋅5458967.

It is a cyclic number.

It is not a de Polignac number, because 1212628709 - 2⁴ = 1212628693 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212628759) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1032317 + ... + 1033490.

It is an arithmetic number, because the mean of its divisors is an integer number (303673776).

Almost surely, 2^1212628709 is an apocalyptic number.

It is an amenable number.

1212628709 is a deficient number, since it is larger than the sum of its proper divisors (2066395).

1212628709 is an equidigital number, since it uses as much as digits as its factorization.

1212628709 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2066394.

The product of its (nonzero) digits is 24192, while the sum is 38.

The square root of 1212628709 is about 34822.8187974495. The cubic root of 1212628709 is about 1066.3733475495.

The spelling of 1212628709 in words is "one billion, two hundred twelve million, six hundred twenty-eight thousand, seven hundred nine".