378781553 has 4 divisors (see below), whose sum is σ = 380704500. Its totient is φ = 376858608.

The previous prime is 378781541. The next prime is 378781561. The reversal of 378781553 is 355187873.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 355187873 = 23 ⋅15442951.

It can be written as a sum of positive squares in 2 ways, for example, as 250367329 + 128414224 = 15823^2 + 11332^2 .

It is a cyclic number.

It is not a de Polignac number, because 378781553 - 2⁶ = 378781489 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 378781498 and 378781507.

It is not an unprimeable number, because it can be changed into a prime (378781523) 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, 961178 + ... + 961571.

It is an arithmetic number, because the mean of its divisors is an integer number (95176125).

Almost surely, 2^378781553 is an apocalyptic number.

It is an amenable number.

378781553 is a deficient number, since it is larger than the sum of its proper divisors (1922947).

378781553 is a wasteful number, since it uses less digits than its factorization.

378781553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1922946.

The product of its digits is 705600, while the sum is 47.

The square root of 378781553 is about 19462.3110909265. The cubic root of 378781553 is about 723.5406573456.

The spelling of 378781553 in words is "three hundred seventy-eight million, seven hundred eighty-one thousand, five hundred fifty-three".