1290287778 has 32 divisors (see below), whose sum is σ = 2874916800. Its totient is φ = 383320896.

The previous prime is 1290287773. The next prime is 1290287813. The reversal of 1290287778 is 8777820921.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 1290287778.

It is not an unprimeable number, because it can be changed into a prime (1290287773) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 282948 + ... + 287471.

It is an arithmetic number, because the mean of its divisors is an integer number (89841150).

Almost surely, 2^1290287778 is an apocalyptic number.

1290287778 is an abundant number, since it is smaller than the sum of its proper divisors (1584629022).

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

1290287778 is a wasteful number, since it uses less digits than its factorization.

1290287778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 570466.

The product of its (nonzero) digits is 790272, while the sum is 51.

The square root of 1290287778 is about 35920.5759697697. The cubic root of 1290287778 is about 1088.6681761311.

The spelling of 1290287778 in words is "one billion, two hundred ninety million, two hundred eighty-seven thousand, seven hundred seventy-eight".