1385665831 has 16 divisors (see below), whose sum is σ = 1534982400. Its totient is φ = 1240360000.

The previous prime is 1385665783. The next prime is 1385665837.

1385665831 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 1385665831 - 2⁹ = 1385665319 is a prime.

It is a super-2 number, since 2×1385665831² = 3840139590401841122, 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 (1385665837) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 242910 + ... + 248548.

It is an arithmetic number, because the mean of its divisors is an integer number (95936400).

Almost surely, 2^1385665831 is an apocalyptic number.

1385665831 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1385665831 is a deficient number, since it is larger than the sum of its proper divisors (149316569).

1385665831 is a wasteful number, since it uses less digits than its factorization.

1385665831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5990.

The product of its digits is 518400, while the sum is 46.

The square root of 1385665831 is about 37224.5326498534. The cubic root of 1385665831 is about 1114.8578665507.

The spelling of 1385665831 in words is "one billion, three hundred eighty-five million, six hundred sixty-five thousand, eight hundred thirty-one".