1068644538 has 144 divisors (see below), whose sum is σ = 2663093160. Its totient is φ = 307777536.

The previous prime is 1068644537. The next prime is 1068644579. The reversal of 1068644538 is 8354468601.

1068644538 is a `hidden beast` number, since 10 + 68 + 6 + 44 + 538 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 540702009 + 527942529 = 23253^2 + 22977^2 .

It is a super-2 number, since 2×1068644538² = 2284002297194466888, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1068644493 and 1068644502.

It is not an unprimeable number, because it can be changed into a prime (1068644537) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 11016906 + ... + 11017002.

Almost surely, 2^1068644538 is an apocalyptic number.

1068644538 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 1068644538, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1331546580).

1068644538 is an abundant number, since it is smaller than the sum of its proper divisors (1594448622).

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

1068644538 is a wasteful number, since it uses less digits than its factorization.

1068644538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 253 (or 227 counting only the distinct ones).

The product of its (nonzero) digits is 552960, while the sum is 45.

The square root of 1068644538 is about 32690.1290606201. The cubic root of 1068644538 is about 1022.3770455311.

The spelling of 1068644538 in words is "one billion, sixty-eight million, six hundred forty-four thousand, five hundred thirty-eight".