1298696778 has 96 divisors (see below), whose sum is σ = 3033675840. Its totient is φ = 401420448.

The previous prime is 1298696753. The next prime is 1298696779. The reversal of 1298696778 is 8776968921.

It is a super-2 number, since 2×1298696778² = 3373226642375162568, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1298696779) 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 47 ways as a sum of consecutive naturals, for example, 8271876 + ... + 8272032.

It is an arithmetic number, because the mean of its divisors is an integer number (31600790).

Almost surely, 2^1298696778 is an apocalyptic number.

1298696778 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1298696778, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1516837920).

1298696778 is an abundant number, since it is smaller than the sum of its proper divisors (1734979062).

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

1298696778 is a wasteful number, since it uses less digits than its factorization.

1298696778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 289 (or 248 counting only the distinct ones).

The product of its digits is 18289152, while the sum is 63.

The square root of 1298696778 is about 36037.4357855827. The cubic root of 1298696778 is about 1091.0280618393.

The spelling of 1298696778 in words is "one billion, two hundred ninety-eight million, six hundred ninety-six thousand, seven hundred seventy-eight".