1311778840 has 16 divisors (see below), whose sum is σ = 2951502480. Its totient is φ = 524711520.

The previous prime is 1311778823. The next prime is 1311778861. The reversal of 1311778840 is 488771131.

It is a Harshad number since it is a multiple of its sum of digits (40), and also a Moran number because the ratio is a prime number: 32794471 = 1311778840 / (1 + 3 + 1 + 1 + 7 + 7 + 8 + 8 + 4 + 0).

It is a junction number, because it is equal to n+sod(n) for n = 1311778793 and 1311778802.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16397196 + ... + 16397275.

It is an arithmetic number, because the mean of its divisors is an integer number (184468905).

Almost surely, 2^1311778840 is an apocalyptic number.

1311778840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1311778840 is an abundant number, since it is smaller than the sum of its proper divisors (1639723640).

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

1311778840 is a wasteful number, since it uses less digits than its factorization.

1311778840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32794482 (or 32794478 counting only the distinct ones).

The product of its (nonzero) digits is 37632, while the sum is 40.

The square root of 1311778840 is about 36218.4875443467. The cubic root of 1311778840 is about 1094.6792190892.

The spelling of 1311778840 in words is "one billion, three hundred eleven million, seven hundred seventy-eight thousand, eight hundred forty".