1538125665 has 16 divisors (see below), whose sum is σ = 2463638976. Its totient is φ = 819454400.

The previous prime is 1538125661. The next prime is 1538125669. The reversal of 1538125665 is 5665218351.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1538125661) and next prime (1538125669).

It is not a de Polignac number, because 1538125665 - 2² = 1538125661 is a prime.

It is a super-2 number, since 2×1538125665² = 4731661122663384450, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1538125661) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 40371 + ... + 68600.

It is an arithmetic number, because the mean of its divisors is an integer number (153977436).

Almost surely, 2^1538125665 is an apocalyptic number.

1538125665 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1538125665 is a deficient number, since it is larger than the sum of its proper divisors (925513311).

1538125665 is a wasteful number, since it uses less digits than its factorization.

1538125665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109920.

The product of its digits is 216000, while the sum is 42.

The square root of 1538125665 is about 39218.9452305898. The cubic root of 1538125665 is about 1154.3316573392.

The spelling of 1538125665 in words is "one billion, five hundred thirty-eight million, one hundred twenty-five thousand, six hundred sixty-five".