1280401920 has 480 divisors, whose sum is σ = 5377477248. Its totient is φ = 274857984.

The previous prime is 1280401919. The next prime is 1280401921. The reversal of 1280401920 is 291040821.

It is an interprime number because it is at equal distance from previous prime (1280401919) and next prime (1280401921).

It is a tau number, because it is divible by the number of its divisors (480).

It is not an unprimeable number, because it can be changed into a prime (1280401921) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2741527 + ... + 2741993.

Almost surely, 2^1280401920 is an apocalyptic number.

1280401920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1280401920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2688738624).

1280401920 is an abundant number, since it is smaller than the sum of its proper divisors (4097075328).

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

1280401920 is a wasteful number, since it uses less digits than its factorization.

1280401920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 520 (or 501 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 1280401920 is about 35782.7042018906. The cubic root of 1280401920 is about 1085.8806783629.

The spelling of 1280401920 in words is "one billion, two hundred eighty million, four hundred one thousand, nine hundred twenty".