1387555631 has 8 divisors (see below), whose sum is σ = 1729939584. Its totient is φ = 1081212120.

The previous prime is 1387555621. The next prime is 1387555649. The reversal of 1387555631 is 1365557831.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1387555631 - 2¹⁰ = 1387554607 is a prime.

It is a super-2 number, since 2×1387555631² = 3850621258239616322, 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 (1387555601) 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 7 ways as a sum of consecutive naturals, for example, 9010025 + ... + 9010178.

It is an arithmetic number, because the mean of its divisors is an integer number (216242448).

Almost surely, 2^1387555631 is an apocalyptic number.

1387555631 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1387555631 is a deficient number, since it is larger than the sum of its proper divisors (342383953).

1387555631 is a wasteful number, since it uses less digits than its factorization.

1387555631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18020221.

The product of its digits is 378000, while the sum is 44.

The square root of 1387555631 is about 37249.9077985436. The cubic root of 1387555631 is about 1115.3644584676.

The spelling of 1387555631 in words is "one billion, three hundred eighty-seven million, five hundred fifty-five thousand, six hundred thirty-one".