1538463681 has 24 divisors (see below), whose sum is σ = 2254150080. Its totient is φ = 1010965536.

The previous prime is 1538463673. The next prime is 1538463727. The reversal of 1538463681 is 1863648351.

1538463681 is a `hidden beast` number, since 1 + 5 + 3 + 8 + 4 + 636 + 8 + 1 = 666.

It is not a de Polignac number, because 1538463681 - 2³ = 1538463673 is a prime.

It is a super-2 number, since 2×1538463681² = 4733740995512139522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1538463631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 361675 + ... + 365903.

It is an arithmetic number, because the mean of its divisors is an integer number (93922920).

Almost surely, 2^1538463681 is an apocalyptic number.

It is an amenable number.

1538463681 is a deficient number, since it is larger than the sum of its proper divisors (715686399).

1538463681 is a wasteful number, since it uses less digits than its factorization.

1538463681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4805 (or 4802 counting only the distinct ones).

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

The square root of 1538463681 is about 39223.2543397409. The cubic root of 1538463681 is about 1154.4162091631.

The spelling of 1538463681 in words is "one billion, five hundred thirty-eight million, four hundred sixty-three thousand, six hundred eighty-one".