1212197643 has 20 divisors (see below), whose sum is σ = 1812363168. Its totient is φ = 807440400.

The previous prime is 1212197639. The next prime is 1212197683. The reversal of 1212197643 is 3467912121.

1212197643 is a `hidden beast` number, since 1 + 2 + 1 + 2 + 1 + 9 + 7 + 643 = 666.

It is not a de Polignac number, because 1212197643 - 2² = 1212197639 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1212197598 and 1212197607.

It is not an unprimeable number, because it can be changed into a prime (1212197603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 99630 + ... + 111132.

Almost surely, 2^1212197643 is an apocalyptic number.

1212197643 is a deficient number, since it is larger than the sum of its proper divisors (600165525).

1212197643 is a wasteful number, since it uses less digits than its factorization.

1212197643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12816 (or 12807 counting only the distinct ones).

The product of its digits is 18144, while the sum is 36.

The square root of 1212197643 is about 34816.6288287651. The cubic root of 1212197643 is about 1066.2469742225.

The spelling of 1212197643 in words is "one billion, two hundred twelve million, one hundred ninety-seven thousand, six hundred forty-three".