1538590681 has 12 divisors (see below), whose sum is σ = 1617381220. Its totient is φ = 1463473440.

The previous prime is 1538590673. The next prime is 1538590717. The reversal of 1538590681 is 1860958351.

It can be written as a sum of positive squares in 2 ways, for example, as 150283081 + 1388307600 = 12259^2 + 37260^2 .

It is not a de Polignac number, because 1538590681 - 2³ = 1538590673 is a prime.

It is a super-2 number, since 2×1538590681² = 4734522567320087522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1538590601) 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, 87715 + ... + 103783.

Almost surely, 2^1538590681 is an apocalyptic number.

It is an amenable number.

1538590681 is a deficient number, since it is larger than the sum of its proper divisors (78790539).

1538590681 is a wasteful number, since it uses less digits than its factorization.

1538590681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16296 (or 16273 counting only the distinct ones).

The product of its (nonzero) digits is 259200, while the sum is 46.

The square root of 1538590681 is about 39224.8732438997. The cubic root of 1538590681 is about 1154.4479739308.

The spelling of 1538590681 in words is "one billion, five hundred thirty-eight million, five hundred ninety thousand, six hundred eighty-one".