1381378665 has 8 divisors (see below), whose sum is σ = 2210205888. Its totient is φ = 736735280.

The previous prime is 1381378657. The next prime is 1381378699. The reversal of 1381378665 is 5668731831.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1381378665 - 2³ = 1381378657 is a prime.

It is a super-2 number, since 2×1381378665² = 3816414032234364450, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 46045941 + ... + 46045970.

It is an arithmetic number, because the mean of its divisors is an integer number (276275736).

Almost surely, 2^1381378665 is an apocalyptic number.

1381378665 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1381378665 is a deficient number, since it is larger than the sum of its proper divisors (828827223).

1381378665 is an equidigital number, since it uses as much as digits as its factorization.

1381378665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92091919.

The product of its digits is 725760, while the sum is 48.

The square root of 1381378665 is about 37166.9028168880. The cubic root of 1381378665 is about 1113.7069112079.

The spelling of 1381378665 in words is "one billion, three hundred eighty-one million, three hundred seventy-eight thousand, six hundred sixty-five".