1280392 has 8 divisors (see below), whose sum is σ = 2400750. Its totient is φ = 640192.

The previous prime is 1280371. The next prime is 1280399. The reversal of 1280392 is 2930821.

1280392 is nontrivially palindromic in base 7.

It can be written as a sum of positive squares in only one way, i.e., 662596 + 617796 = 814^2 + 786^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (1280399) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80017 + ... + 80032.

2^1280392 is an apocalyptic number.

It is an amenable number.

1280392 is a deficient number, since it is larger than the sum of its proper divisors (1120358).

1280392 is a wasteful number, since it uses less digits than its factorization.

1280392 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160055 (or 160051 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 1280392 is about 1131.5440777981. The cubic root of 1280392 is about 108.5877874044.

The spelling of 1280392 in words is "one million, two hundred eighty thousand, three hundred ninety-two".