1381877491 has 4 divisors (see below), whose sum is σ = 1389037672. Its totient is φ = 1374717312.

The previous prime is 1381877477. The next prime is 1381877507. The reversal of 1381877491 is 1947781831.

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

It is a cyclic number.

It is not a de Polignac number, because 1381877491 - 2⁵ = 1381877459 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1381877461) 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, 3579801 + ... + 3580186.

It is an arithmetic number, because the mean of its divisors is an integer number (347259418).

Almost surely, 2^1381877491 is an apocalyptic number.

1381877491 is a deficient number, since it is larger than the sum of its proper divisors (7160181).

1381877491 is an equidigital number, since it uses as much as digits as its factorization.

1381877491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7160180.

The product of its digits is 338688, while the sum is 49.

The square root of 1381877491 is about 37173.6128322228. The cubic root of 1381877491 is about 1113.8409509950.

The spelling of 1381877491 in words is "one billion, three hundred eighty-one million, eight hundred seventy-seven thousand, four hundred ninety-one".