1538428778 has 8 divisors (see below), whose sum is σ = 2336854080. Its totient is φ = 759477420.

The previous prime is 1538428777. The next prime is 1538428819. The reversal of 1538428778 is 8778248351.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (1538428777) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4868288 + ... + 4868603.

It is an arithmetic number, because the mean of its divisors is an integer number (292106760).

Almost surely, 2^1538428778 is an apocalyptic number.

1538428778 is a deficient number, since it is larger than the sum of its proper divisors (798425302).

1538428778 is an equidigital number, since it uses as much as digits as its factorization.

1538428778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9736972.

The product of its digits is 3010560, while the sum is 53.

The square root of 1538428778 is about 39222.8094098319. The cubic root of 1538428778 is about 1154.4074790483.

The spelling of 1538428778 in words is "one billion, five hundred thirty-eight million, four hundred twenty-eight thousand, seven hundred seventy-eight".