1365221538 has 24 divisors (see below), whose sum is σ = 2959705008. Its totient is φ = 454808472.

The previous prime is 1365221531. The next prime is 1365221551. The reversal of 1365221538 is 8351225631.

It is a super-3 number, since 3×1365221538³ (a number of 28 digits) contains 333 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1365221531) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10945 + ... + 53387.

It is an arithmetic number, because the mean of its divisors is an integer number (123321042).

Almost surely, 2^1365221538 is an apocalyptic number.

1365221538 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

1365221538 is an abundant number, since it is smaller than the sum of its proper divisors (1594483470).

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

1365221538 is a wasteful number, since it uses less digits than its factorization.

1365221538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44238 (or 44235 counting only the distinct ones).

The product of its digits is 43200, while the sum is 36.

The square root of 1365221538 is about 36948.9044221882. The cubic root of 1365221538 is about 1109.3477590116.

The spelling of 1365221538 in words is "one billion, three hundred sixty-five million, two hundred twenty-one thousand, five hundred thirty-eight".