1388500081 has 4 divisors (see below), whose sum is σ = 1388622564. Its totient is φ = 1388377600.

The previous prime is 1388500079. The next prime is 1388500153. The reversal of 1388500081 is 1800058831.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 536385600 + 852114481 = 23160^2 + 29191^2 .

It is a cyclic number.

It is not a de Polignac number, because 1388500081 - 2¹ = 1388500079 is a prime.

It is a super-2 number, since 2×1388500081² = 3855864949874013122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1388500681) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 42280 + ... + 67561.

It is an arithmetic number, because the mean of its divisors is an integer number (347155641).

Almost surely, 2^1388500081 is an apocalyptic number.

It is an amenable number.

1388500081 is a deficient number, since it is larger than the sum of its proper divisors (122483).

1388500081 is a wasteful number, since it uses less digits than its factorization.

1388500081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122482.

The product of its (nonzero) digits is 7680, while the sum is 34.

The square root of 1388500081 is about 37262.5828546546. The cubic root of 1388500081 is about 1115.6174614288.

The spelling of 1388500081 in words is "one billion, three hundred eighty-eight million, five hundred thousand, eighty-one".