1291928780 has 24 divisors (see below), whose sum is σ = 2751265440. Its totient is φ = 509492480.

The previous prime is 1291928777. The next prime is 1291928783. The reversal of 1291928780 is 878291921.

It is an interprime number because it is at equal distance from previous prime (1291928777) and next prime (1291928783).

It is not an unprimeable number, because it can be changed into a prime (1291928783) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 453485 + ... + 456324.

It is an arithmetic number, because the mean of its divisors is an integer number (114636060).

Almost surely, 2^1291928780 is an apocalyptic number.

1291928780 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1291928780 is an abundant number, since it is smaller than the sum of its proper divisors (1459336660).

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

1291928780 is a wasteful number, since it uses less digits than its factorization.

1291928780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 909889 (or 909887 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 47.

The square root of 1291928780 is about 35943.4108008686. The cubic root of 1291928780 is about 1089.1295072784.

The spelling of 1291928780 in words is "one billion, two hundred ninety-one million, nine hundred twenty-eight thousand, seven hundred eighty".