1223999920 has 80 divisors (see below), whose sum is σ = 3343348512. Its totient is φ = 410849280.

The previous prime is 1223999891. The next prime is 1223999963. The reversal of 1223999920 is 299993221.

It is a tau number, because it is divible by the number of its divisors (80).

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 15 ways as a sum of consecutive naturals, for example, 42057 + ... + 64936.

Almost surely, 2^1223999920 is an apocalyptic number.

1223999920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1223999920 is an abundant number, since it is smaller than the sum of its proper divisors (2119348592).

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

1223999920 is a wasteful number, since it uses less digits than its factorization.

1223999920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107030 (or 107024 counting only the distinct ones).

The product of its (nonzero) digits is 157464, while the sum is 46.

The square root of 1223999920 is about 34985.7102257479. The cubic root of 1223999920 is about 1069.6962249429.

It can be divided in two parts, 12 and 23999920, that added together give a palindrome (23999932).

The spelling of 1223999920 in words is "one billion, two hundred twenty-three million, nine hundred ninety-nine thousand, nine hundred twenty".