1385853781 has 4 divisors (see below), whose sum is σ = 1492457932. Its totient is φ = 1279249632.

The previous prime is 1385853779. The next prime is 1385853811. The reversal of 1385853781 is 1873585831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1873585831 = 13 ⋅144121987.

It can be written as a sum of positive squares in 2 ways, for example, as 149206225 + 1236647556 = 12215^2 + 35166^2 .

It is a cyclic number.

It is not a de Polignac number, because 1385853781 - 2¹ = 1385853779 is a prime.

It is a super-2 number, since 2×1385853781² = 3841181404623991922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1385853181) 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, 53302056 + ... + 53302081.

It is an arithmetic number, because the mean of its divisors is an integer number (373114483).

Almost surely, 2^1385853781 is an apocalyptic number.

It is an amenable number.

1385853781 is a deficient number, since it is larger than the sum of its proper divisors (106604151).

1385853781 is a wasteful number, since it uses less digits than its factorization.

1385853781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106604150.

The product of its digits is 806400, while the sum is 49.

The square root of 1385853781 is about 37227.0571090437. The cubic root of 1385853781 is about 1114.9082702527.

The spelling of 1385853781 in words is "one billion, three hundred eighty-five million, eight hundred fifty-three thousand, seven hundred eighty-one".