1280779776 has 200 divisors, whose sum is σ = 3876883560. Its totient is φ = 420913152.

The previous prime is 1280779763. The next prime is 1280779789. The reversal of 1280779776 is 6779770821.

It is an interprime number because it is at equal distance from previous prime (1280779763) and next prime (1280779789).

It is a super-2 number, since 2×1280779776² = 3280793669221220352, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 3690835 + ... + 3691181.

Almost surely, 2^1280779776 is an apocalyptic number.

1280779776 is a gapful number since it is divisible by the number (16) 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 1280779776, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1938441780).

1280779776 is an abundant number, since it is smaller than the sum of its proper divisors (2596103784).

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

1280779776 is an frugal number, since it uses more digits than its factorization.

1280779776 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 466 (or 441 counting only the distinct ones).

The product of its (nonzero) digits is 2074464, while the sum is 54.

The square root of 1280779776 is about 35787.9836816773. The cubic root of 1280779776 is about 1085.9874849753.

The spelling of 1280779776 in words is "one billion, two hundred eighty million, seven hundred seventy-nine thousand, seven hundred seventy-six".