1340047391 has 4 divisors (see below), whose sum is σ = 1340422512. Its totient is φ = 1339672272.

The previous prime is 1340047381. The next prime is 1340047393. The reversal of 1340047391 is 1937400431.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1937400431 = 3299 ⋅587269.

It is a cyclic number.

It is not a de Polignac number, because 1340047391 - 2⁶ = 1340047327 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1340047393) 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, 182150 + ... + 189363.

It is an arithmetic number, because the mean of its divisors is an integer number (335105628).

Almost surely, 2^1340047391 is an apocalyptic number.

1340047391 is a deficient number, since it is larger than the sum of its proper divisors (375121).

1340047391 is an equidigital number, since it uses as much as digits as its factorization.

1340047391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 375120.

The product of its (nonzero) digits is 9072, while the sum is 32.

The square root of 1340047391 is about 36606.6577414546. The cubic root of 1340047391 is about 1102.4867681459.

The spelling of 1340047391 in words is "one billion, three hundred forty million, forty-seven thousand, three hundred ninety-one".