1212640065 has 120 divisors (see below), whose sum is σ = 2691171648. Its totient is φ = 511505280.

The previous prime is 1212640049. The next prime is 1212640087. The reversal of 1212640065 is 5600462121.

1212640065 is a `hidden beast` number, since 1 + 2 + 12 + 640 + 0 + 6 + 5 = 666.

It is not a de Polignac number, because 1212640065 - 2⁴ = 1212640049 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 477850 + ... + 480380.

Almost surely, 2^1212640065 is an apocalyptic number.

1212640065 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1212640065 is an abundant number, since it is smaller than the sum of its proper divisors (1478531583).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1212640065 is a wasteful number, since it uses less digits than its factorization.

1212640065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2581 (or 2559 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 1212640065 is about 34822.9818510707. The cubic root of 1212640065 is about 1066.3766763227.

The spelling of 1212640065 in words is "one billion, two hundred twelve million, six hundred forty thousand, sixty-five".