1387662181 has 4 divisors (see below), whose sum is σ = 1396975500. Its totient is φ = 1378348864.

The previous prime is 1387662173. The next prime is 1387662187. The reversal of 1387662181 is 1812667831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1812667831 = 13 ⋅139435987.

It can be written as a sum of positive squares in 2 ways, for example, as 528586081 + 859076100 = 22991^2 + 29310^2 .

It is a cyclic number.

It is not a de Polignac number, because 1387662181 - 2³ = 1387662173 is a prime.

It is a super-2 number, since 2×1387662181² = 3851212657155353522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1387662187) 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, 4656436 + ... + 4656733.

It is an arithmetic number, because the mean of its divisors is an integer number (349243875).

Almost surely, 2^1387662181 is an apocalyptic number.

It is an amenable number.

1387662181 is a deficient number, since it is larger than the sum of its proper divisors (9313319).

1387662181 is an equidigital number, since it uses as much as digits as its factorization.

1387662181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9313318.

The product of its digits is 96768, while the sum is 43.

The square root of 1387662181 is about 37251.3379759707. The cubic root of 1387662181 is about 1115.3930072428.

The spelling of 1387662181 in words is "one billion, three hundred eighty-seven million, six hundred sixty-two thousand, one hundred eighty-one".