3648129778 has 4 divisors (see below), whose sum is σ = 5472194670. Its totient is φ = 1824064888.

The previous prime is 3648129721. The next prime is 3648129787. The reversal of 3648129778 is 8779218463.

3648129778 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 8779218463 = 19927 ⋅440569.

It can be written as a sum of positive squares in only one way, i.e., 2666999449 + 981130329 = 51643^2 + 31323^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 912032443 + ... + 912032446.

Almost surely, 2^3648129778 is an apocalyptic number.

3648129778 is a deficient number, since it is larger than the sum of its proper divisors (1824064892).

3648129778 is a wasteful number, since it uses less digits than its factorization.

3648129778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1824064891.

The product of its digits is 4064256, while the sum is 55.

The square root of 3648129778 is about 60399.7498173627. The cubic root of 3648129778 is about 1539.4187070742.

The spelling of 3648129778 in words is "three billion, six hundred forty-eight million, one hundred twenty-nine thousand, seven hundred seventy-eight".