1318720428 has 18 divisors (see below), whose sum is σ = 3333432284. Its totient is φ = 439573464.

The previous prime is 1318720397. The next prime is 1318720457. The reversal of 1318720428 is 8240278131.

1318720428 is a `hidden beast` number, since 131 + 87 + 20 + 428 = 666.

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 36631123 = 1318720428 / (1 + 3 + 1 + 8 + 7 + 2 + 0 + 4 + 2 + 8).

It is a junction number, because it is equal to n+sod(n) for n = 1318720392 and 1318720401.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 18315526 + ... + 18315597.

Almost surely, 2^1318720428 is an apocalyptic number.

1318720428 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

1318720428 is an abundant number, since it is smaller than the sum of its proper divisors (2014711856).

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

1318720428 is a wasteful number, since it uses less digits than its factorization.

1318720428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36631133 (or 36631128 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 36.

The square root of 1318720428 is about 36314.1904494648. The cubic root of 1318720428 is about 1096.6067410994.

Adding to 1318720428 its reverse (8240278131), we get a palindrome (9558998559).

The spelling of 1318720428 in words is "one billion, three hundred eighteen million, seven hundred twenty thousand, four hundred twenty-eight".