1387443491 has 32 divisors (see below), whose sum is σ = 1743431040. Its totient is φ = 1076576256.

The previous prime is 1387443481. The next prime is 1387443503. The reversal of 1387443491 is 1943447831.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-1387443491 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1387443481) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1162391 + ... + 1163583.

It is an arithmetic number, because the mean of its divisors is an integer number (54482220).

Almost surely, 2^1387443491 is an apocalyptic number.

1387443491 is a deficient number, since it is larger than the sum of its proper divisors (355987549).

1387443491 is a wasteful number, since it uses less digits than its factorization.

1387443491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1583.

The product of its digits is 290304, while the sum is 44.

The square root of 1387443491 is about 37248.4025295045. The cubic root of 1387443491 is about 1115.3344103415.

The spelling of 1387443491 in words is "one billion, three hundred eighty-seven million, four hundred forty-three thousand, four hundred ninety-one".