1272205920 has 48 divisors (see below), whose sum is σ = 4007450160. Its totient is φ = 339254784.

The previous prime is 1272205919. The next prime is 1272205927. The reversal of 1272205920 is 295022721.

It is a tau number, because it is divible by the number of its divisors (48).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1272205927) 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 7 ways as a sum of consecutive naturals, for example, 1324735 + ... + 1325694.

It is an arithmetic number, because the mean of its divisors is an integer number (83488545).

Almost surely, 2^1272205920 is an apocalyptic number.

1272205920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1272205920 is an abundant number, since it is smaller than the sum of its proper divisors (2735244240).

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

1272205920 is a wasteful number, since it uses less digits than its factorization.

1272205920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2650447 (or 2650439 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 30.

The square root of 1272205920 is about 35667.9957384768. The cubic root of 1272205920 is about 1083.5587679702.

The spelling of 1272205920 in words is "one billion, two hundred seventy-two million, two hundred five thousand, nine hundred twenty".