1385823817 has 4 divisors (see below), whose sum is σ = 1583798656. Its totient is φ = 1187848980.

The previous prime is 1385823809. The next prime is 1385823827. The reversal of 1385823817 is 7183285831.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 7183285831 = 401 ⋅17913431.

It is a cyclic number.

It is not a de Polignac number, because 1385823817 - 2³ = 1385823809 is a prime.

It is a super-4 number, since 4×1385823817⁴ (a number of 38 digits) contains 4444 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1385823827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 98987409 + ... + 98987422.

It is an arithmetic number, because the mean of its divisors is an integer number (395949664).

Almost surely, 2^1385823817 is an apocalyptic number.

It is an amenable number.

1385823817 is a deficient number, since it is larger than the sum of its proper divisors (197974839).

1385823817 is an equidigital number, since it uses as much as digits as its factorization.

1385823817 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 197974838.

The product of its digits is 322560, while the sum is 46.

The square root of 1385823817 is about 37226.6546576509. The cubic root of 1385823817 is about 1114.9002349288.

It can be divided in two parts, 13858 and 23817, that added together give a triangular number (37675 = T₂₇₄).

The spelling of 1385823817 in words is "one billion, three hundred eighty-five million, eight hundred twenty-three thousand, eight hundred seventeen".