1212405664 has 24 divisors (see below), whose sum is σ = 2400269760. Its totient is φ = 602813376.

The previous prime is 1212405661. The next prime is 1212405673. The reversal of 1212405664 is 4665042121.

It is a happy number.

It is a super-5 number, since 5×1212405664⁵ (a number of 47 digits) contains 55555 as substring.

It is not an unprimeable number, because it can be changed into a prime (1212405661) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 100104 + ... + 111559.

It is an arithmetic number, because the mean of its divisors is an integer number (100011240).

Almost surely, 2^1212405664 is an apocalyptic number.

It is an amenable number.

1212405664 is a deficient number, since it is larger than the sum of its proper divisors (1187864096).

1212405664 is a wasteful number, since it uses less digits than its factorization.

1212405664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 211852 (or 211844 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 31.

The square root of 1212405664 is about 34819.6160805946. The cubic root of 1212405664 is about 1066.3079623727.

Adding to 1212405664 its reverse (4665042121), we get a palindrome (5877447785).

The spelling of 1212405664 in words is "one billion, two hundred twelve million, four hundred five thousand, six hundred sixty-four".