378861665535 has 24 divisors (see below), whose sum is σ = 659993536800. Its totient is φ = 201044175552.

The previous prime is 378861665531. The next prime is 378861665579. The reversal of 378861665535 is 535566168873.

It is a happy number.

378861665535 is a `hidden beast` number, since 3 + 7 + 8 + 8 + 616 + 6 + 5 + 5 + 3 + 5 = 666.

It is not a de Polignac number, because 378861665535 - 2² = 378861665531 is a prime.

It is a super-2 number, since 2×378861665535² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (378861665531) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 21144684 + ... + 21162593.

It is an arithmetic number, because the mean of its divisors is an integer number (27499730700).

Almost surely, 2^378861665535 is an apocalyptic number.

378861665535 is a deficient number, since it is larger than the sum of its proper divisors (281131871265).

378861665535 is a wasteful number, since it uses less digits than its factorization.

378861665535 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42307487 (or 42307484 counting only the distinct ones).

The product of its digits is 108864000, while the sum is 63.

The spelling of 378861665535 in words is "three hundred seventy-eight billion, eight hundred sixty-one million, six hundred sixty-five thousand, five hundred thirty-five".