1365481638 has 48 divisors (see below), whose sum is σ = 3105176256. Its totient is φ = 449663400.

The previous prime is 1365481627. The next prime is 1365481639. The reversal of 1365481638 is 8361845631.

1365481638 is a `hidden beast` number, since 1 + 3 + 6 + 5 + 4 + 8 + 1 + 638 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 1365481593 and 1365481602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1365481639) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 23413 + ... + 57263.

It is an arithmetic number, because the mean of its divisors is an integer number (64691172).

Almost surely, 2^1365481638 is an apocalyptic number.

1365481638 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1365481638, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1552588128).

1365481638 is an abundant number, since it is smaller than the sum of its proper divisors (1739694618).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1365481638 is an equidigital number, since it uses as much as digits as its factorization.

1365481638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33951 (or 33939 counting only the distinct ones).

The product of its digits is 414720, while the sum is 45.

The square root of 1365481638 is about 36952.4239800314. The cubic root of 1365481638 is about 1109.4182049726.

The spelling of 1365481638 in words is "one billion, three hundred sixty-five million, four hundred eighty-one thousand, six hundred thirty-eight".