1283257840 has 40 divisors (see below), whose sum is σ = 2994169968. Its totient is φ = 511480320.

The previous prime is 1283257819. The next prime is 1283257849. The reversal of 1283257840 is 487523821.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 1283257793 and 1283257802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1283257849) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5701 + ... + 50980.

Almost surely, 2^1283257840 is an apocalyptic number.

1283257840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1283257840 is an abundant number, since it is smaller than the sum of its proper divisors (1710912128).

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

1283257840 is a wasteful number, since it uses less digits than its factorization.

1283257840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56977 (or 56971 counting only the distinct ones).

The product of its (nonzero) digits is 107520, while the sum is 40.

The square root of 1283257840 is about 35822.5884045249. The cubic root of 1283257840 is about 1086.6874264710.

The spelling of 1283257840 in words is "one billion, two hundred eighty-three million, two hundred fifty-seven thousand, eight hundred forty".